Teaching general problem-solving skills is not a substitute for teaching math [pdf] (2010)
ams.org
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Amusingly, many people think the solution to this is "abandon worked examples and focus exclusively on trying to teach general problem-solving skills," which doesn't really work in practice (or even in theory). That seems to be the most common approach in higher math, especially once you get into serious math-major courses like Real Analysis and Abstract Algebra.
What actually works in practice is simply creating more worked examples, organizing them well, and giving students practice with problems like each worked example before moving them onto the next worked example covering a slightly more challenging case. You can get really, really far with this approach, but most educational resources shy away from it or give up really early because it's so much damn work! ;)
The studies you refer to are demonstrating that active/unguided is superior to passive/direct.
But the full picture is that active/direct > active/unguided > passive/direct. (I didn't include passive/unguided here because I'm not sure it's possible to create such a combination.)
Other studies -- that only manipulate one variable at a time -- support this big picture.
Its possible, we call the end result LLM. It isn't very effective though as we can see from the result and how much learning it took.
To me though the more interesting result isn’t really about pedagogy, it’s that people’s (undergrad physics students, in the case of the specific study I’m thinking of) subjective impressions of the effectiveness of instruction are unreliable.
Yes, common finding in studies that explore subjective vs objective measurements of learning under conditions involving "desirable difficulties":
My undergraduate math professor was like that, and he was pretty brutal, but by the end of the 2nd semester it was pretty clear who was going to end up majoring in something to do with math and who wasn't. From a pure selection standpoint, this makes sense to me. On the other hand, for those who "won't" it can make the experience pretty miserable.
I'm probably confusing people with my use of the word "will" in this context, since it can mean several things in English. What I'm really saying is that those who have the actual aptitude "will derive complex concepts on their own, and will be likely to pursue further their math education". It's already difficult to identify those people when they're young enough, and even harder if you teach math in a "lowest common denominator" approach, which is essentially what the American strategy is (with notable exceptions that probably just prove the rule).
At what point would you say they've actually acquired the skill?
Even then, before you get to that point, you have to prime students for it. Throwing them into the deep end without teaching them to float first will only set them up to drown. This does typically mean lots of worked motivating (counter-)examples at the outset.
It's a big reason why we spent so long on continuity and differentiability in my undergraduate real analysis class and why most of the class discussion there centered on when a function could be continuous everywhere but nowhere differentiable. Left to our own devices and without that guidance, our intuition would certainly be too flawed for such a fundamental part of the material.
But in realistic functions relevant to our actually universe, these pathological cases aren't important.
I would personally not consider it fundamental either though, more of a “let’s cross that bridge when we get to it” problem.
Is this supported by research though? As I understand it, for students (not experts), empirical results point in the opposite direction.
One key empirical result is the "expertise reversal effect," a well-known phenomenon that instructional techniques that promote the most learning in experts, promote the least learning in beginners, and vice versa.
It's true that many highly skilled professionals spend a lot of time solving open-ended problems, and in the process, discovering new knowledge as opposed to obtaining it through direct instruction. But I don't think this means beginners should do the same. The expertise reversal effect suggests the opposite – that beginners (i.e., students) learn most effectively through direct instruction.
Here are some quotes elaborating on why beginners benefit more from direct instruction:
1. "First, a learner who is having difficulty with many of the components can easily be overwhelmed by the processing demands of the complex task. Second, to the extent that many components are well mastered, the student will waste a great deal of time repeating those mastered components to get an opportunity to practice the few components that need additional practice.
A large body of research in psychology shows that part training is often more effective when the part component is independent, or nearly so, of the larger task. ... Practicing one's skills periodically in full context is important to motivation and to learning to practice, but not a reason to make this the principal mechanism of learning."
^ from Radical Constructivism and Cognitive Psychology (Anderson, Reder, & Simon, 1998) - https://www.andrew.cmu.edu/user/reder/publications/98_jra_lm...
2. "These two facts -- that working memory is very limited when dealing with novel information, but that it is not limited when dealing with organized information stored in long-term memory -- explain why partially or minimally guided instruction typically is ineffective for novices, but can be effective for experts. When given a problem to solve, novices' only resource is their very constrained working memory. But experts have both their working memory and all the relevant knowledge and skill stored in long-term memory."
^ from Putting Students on the Path to Learning (Clark, Kirschner, & Sweller, 2012) - https://files.eric.ed.gov/fulltext/EJ971752.pdf
And some other references:
* Why Minimal Guidance During Instruction Does Not Work: An Analysis of the Failure of Constructivist, Discovery, Problem-Based, Experiential, and Inquiry-Based Teaching - https://www.tandfonline.com/doi/pdf/10.1207/s15326985ep4102_...
* Should There Be a Three-Strikes Rule Against Pure Discovery Learning? The Case for Guided Methods of Instruction - https://app.nova.edu/toolbox/instructionalproducts/ITDE_8005...
Intuitively, too: in an hour-long session, you're going to make a lot more progress by solving 30 problems that each take 2 minutes given your current level of knowledge, than by attempting a single challenge problem that you struggle with for an hour. (This assumes those 30 problems are grouped into minimal effective doses, well-scaffolded & increasing in difficulty, across a variety of topics at the edge of your knowledge profile.)
To be clear, I'm not claiming that "challenge problems" are bad -- I'm just saying that they're not a good use of time until you've developed the foundational skills that are necessary to grapple with those problems in a productive and timely fashion.
I don't have nearly as impressive a backstory as you do here, but I did apply spaced repetition to my abstract algebra class in my math minor a few years back. I didn't do anything fancy, I just put every homework problem and proof into Anki and solved/rederived them over and over again until I could do so without much thinking.
I ended up walking out with a perfect score on the 2 hour final - in about 15 minutes. Most of the problems were totally novel things I had never seen before, but the fluency I gained in the weeks prior just unlocked something in me. A lot of the concepts of group actions, etc. have stuck with me to this very day, heavily informing my approach to software engineering. Great stuff.
That was the bane of my University degree. "And, since our function f happens to be of this form, all the difficult stuff cancels out and we're left with this trivial stuff" and then none of the problems have these "happy accident" cancellations and you're none the wiser on how to proceed.
The statistics book we used was an especially egregious offender in this regard.
Two I remember were:
- In an early geometry course there was a problem to prove/determine something described in terms of the Poincaré disc model of the hyperbolic plane. The trick was to convert to the upper half-plane model (where there was an obvious choice for which point on the boundary of the disc maps to infinity in the uhp). There I was annoyed because it felt like a trick question, but the lesson was probably useful.
- in a topology course there was a problem like ‘find a space which deformation-retracts to a möbius strip and to an annulus. This is easy to imagine in your head: a solid torus = S1*D2 can contain an embedding of each of those spaces into R3. I ended up carefully writing those retractions by hand, but I think the better solution was to take the product space and apply some theorems (I think I’m misremembering this – product space works for an ordinary retraction but for the deformation retraction I don’t think it works. I guess both retract to S1 and you could glue the two spaces together along that, or use the proof that homotopy equivalence <=> deformation retracts from common space, but I don’t think we had that). I felt less annoyed at missing the trick there.
[1] I’m really talking about exercises here. I don’t really recall having problems with the examples.
Many students will look only at examples in the textbook and happily ignore definitions, theorems, and proofs. They don't know whether the strategy they picked works, only that it worked on a similar looking problem.
Sure, when (good) teachers explain the example they do go through the effort of referring to the definitions and theorems, but that is not necessarily what the students remember.
I think that’s a problem with differential equations as a subject. The only ones we know how to solve are special cases. Solving them in general is an open problem.
It's not "problem solving", it's the deeper understanding of a discipline which makes the experienced practionner go one way rather than the other.
And it doesn't necessarily have to be math. You can also train yourself by memorizing poetry, Chinese characters, foreign language words, and so on. And somehow all of these activities are getting sidelined in the modern education. After all, what use is memorization when you can always look up the answer on a phone?
Memorizing all of the theorems you need, proofs, and a diverse set of examples is going to make it substantially easier to approach new problems.
I've heard it from people conducting interviews, when we're discussing what we want from candidates: "I'm not looking for memorization, I'm looking for problem solving!" - if you've memorized 1000 problems, you'll be better at problem solving than if you didn't!
There are lots of folk who can remember all sorts of details but never seem to be able to figure out how to put the pieces together.
(For jor can inte far opp min kokosnutt btw)
I think the commenters need to agree on a more-nuanced set of terms to reach agreement on this.
But "understanding" on its own doesn't allow you to reproduce a textbook full of theorems, you have to actually study and memorize at least a bit.
Once, in medieval times, rote memorization was a large part of the education process. This system was renowned for not producing flexible or imaginative thinkers. Medieval times produced very significant mathematicians, notably and mathematical advances actually detoured around medieval Europe, going from ancient Rome and Greece to India and the Muslim world and returning to Italy with the Renaissance.
I think people are trying to say memorising is critical, understanding follows, not leads. Sure, I think those posters framing things this way are incorrect. Problem solving may be something one learns and remembers but rote memorization, as in the medieval trivium, isn't significant part of such learning.
This really hit me as someone who did the overachievey college math. None of it sticks with me at all unless I can think about "what it's for."
Corollary: When I was a kid, we didn't have the thing we have now which strikes me as the CLEAR USE CASE -- video game development; such a no-brainer for me.
X Y algebra? Oh, you mean making a rainbow in Minecraft? :)
Twenty years ago, when I was in college, I remember a classmate had problems installing the particular software we needed to use. The teacher told her that the only solution would be to install Linux on her laptop. All the other students had managed to install that software on their Windows laptops. The teacher was either one step ahead or 25 steps behind.
Not true.
There are other examples. I wouldn't be motivated to analyze some filter circuit's transfer function if it's not related to guitar somehow.
If you are someone who is primarily about Making Stuff, this will resonate.
I think some of the academics in math are not Make Stuff people; they can get motivated by the math itself. Or, well, maybe they are Make Stuff people, but what hey make is the math itself. Their application for something is, oh, I need that to prove this other thing in some structure I'm making.
I've experienced the Make Stuff motivation playing with just math. For instance, in high school, I independently came up with double and triple integration along multiple a, and used that to work out the volumes of common solids (easily verifiable to be right). I was thinking, I'm following this cool idea where we integrate along one variable, to get a formula which we integrate along another; will that work?
But probably, greed/money would be the other.
Now, that's probably a whole other conversation, given the propensity that "capitalism" or whatever one wants to call it is pretty much dedicated to you and I getting this wrong consistently, but hey.
Not saying that higher math would be "easy" if taught properly. Just that many more people would be able to learn it, than are currently able to learn it.
Higher math is heavily g-loaded, which creates a cognitive barrier for many students. The goal of guided/scaffolded instruction is to help boost students over that barrier. Of course, the amount of work it takes to create a textbook explodes with the level of guidance/scaffolding, so in practice there's a limit to the amount of boosting that is feasible, especially if the textbook is written entirely by a single author... but most textbooks don't even come close to the theoretical limit for a single author, much less the theoretical limit for a team of content writers.
1) What is "g"?
"g" is "general intelligence." IQ is a specific measurement of g.
https://en.wikipedia.org/wiki/G_factor_(psychometrics)
2) What is g-"loaded"?
This is a good summary: https://www.reddit.com/r/cogsci/comments/j5pug9/comment/g7u4...
"it's the degree to which that test correlates with g. A relatively high g-loaded test will have a higher correlation with g, meaning that performance on the test is more indicative of g than performance on a test that is less g-loaded. Often greater complexity or how much mental manipulation a test requires results in a higher g-loaded test. In contrast, higher difficulty (as measured by the percentage of people who fail) does not always mean higher g-loading. For instance, tests of reasoning are generally more g-loaded than tests of rote memorization even when the tests are of equal difficulty." - oscarjeff on Reddit
1. "Concrete" math, where you learn how to manipulate mathematical constructs, usually guided by worked examples. Little proof involved. (up to advanced HS / junior college level)
2. Proof driven math, use of worked examples becomes more rare (undergrad math)
3. Highly abstract math, where worked examples are more or less entirely abandoned (grad school math)
The vast majority of world will never be exposed to math beyond (1), and even people in the STEM field will only be limited to (2). You almost need to study math at a high level, or something very adjacent to math, in order to reach (3).
But it should be mentioned that one part of why worked examples diminish as you work your way up, is that you're kind of expected to make your own examples - meaning that you can take highly abstracted mathematical constructs/objects, and relate them to something tangible.
Some people have no problem learning math that way, while others struggle. I personally struggled to learn math without any examples, so getting my mind into graduate level math was rough.
Luckily there are so many resources to higher-level math, these days. You're not bound to a handful of "bibles" that are filled with "... is left as an exercise for the reader"
Higher math is a big exercise in shifting symbols around. If you don't have an intrinsic motivation to solve puzzles you will hate higher math.
Even Grothendieck, who was famously known for thinking very abstractly and avoiding examples, was motivated by concrete questions (e.g., the Weil conjectures) coming from concrete examples. To me, and most other mathematicians, the whole point of mathematics is to do examples, and theory building or any other abstract nonsense should be motivated by the desire to better understand or unify examples.
You can teach software engineering in school. But you become an expert by reading source code and seeing the many ways to solve a problem.
An expert can intuit a solution because of pattern matching. And their argument is that math is the same.
More so by iteratively building, at least so for me.
Computer science/software engineering as taught in school gives a lot of foundational and theoretical understanding. But to apply and practice that knowledge,” then
General problem-solving skills aren't a substitute for special skills.
General problem-solving skills have limits; one of the outcomes of general problem solving is the conclusion "I don't know how to solve this; it may require someone with special skills".
Without properly honed general skills, you may waste time avoiding this correct conclusion (among other mistakes). General skills let you undestand what the problem actually is, what a solution looks like, and whether you are getting closer.
edit - corrected spelling
A little while back I wrote about cultural literacy in the software industry, following the lead of Hirsch's book.[2]
1. https://hep.gse.harvard.edu/9781612509525/why-knowledge-matt...
2. https://thundergolfer.com/software/culture/2024/01/14/comput...
But if one means pure rote memorization, I think the value depends very much on the field. Writing English requires knowledge of the spellings of words since English spellings are fairly arbitrary. A student can benefit from memorizing multiplication table to 10 but they'd do better learning principles than memorization multiplication up 100 or 1000. And many of principles, terminologies and rules of thumb are best remembered in-context.
One thing to consider is that "memory training" approaches can be effectively used to remember long arbitrary sequences of data (the arrangement of a deck of playing cards or whatever) through adding colorful/memorable (but arbitrary) associations.
But such methods are seldom actually used by practitioners of memory intensive fields. Usually such practitioners need to recall facts and ideas in context and so they achieve a high recall naturally, by associations facts and ideas with each other.
Furthermore, what audience and level of mathematics education are we discussing? The goals (and hence appropriate metrics of success) are certainly different for high schoolers targeting non-STEM careers vs. engineering undergrads vs. math grad students. The authors reference "aspiring mathematicians" and "domain specific mathematical problem-solving skills", indicating they're arguing about education for math majors, or at least students in STEM fields. In that case, the argument is somewhat meaningless - who's arguing math majors shouldn't learn math-specific skills? But, as I understand it, the argument for general problem-solving skills is that students outside of math don't actually need many specific math skills. Instead, math is a vessel for teaching logic, reasoning, and problem-solving skills. Then again, this might not be the type of problem-solving the authors are referencing - as I said above, it's not very clear.
On a similar note, they cite evidence that studying worked examples is more effective than "general problem-solving strategies", citing an "improvement in subsequent problem-solving performance" without explaining how this performance is measured. If students are tested on specific problem types, of course they'll perform better when taught strategies for those specific problem types. But it's not clear that this is meaningful. For STEM majors, sure, solving specific problems is a skill worth cultivating. But for most students, solving specific problems isn't as important as learning logic, reasoning, and general problem-solving skills. In my anecdotal experience tutoring math, students tend to just memorize strategies for specific problem types instead of learning transferable logic and reasoning skills because that's what's tested. I'd be curious to see which method of learning facilitates better performance on a more general problem-solving test of some sort.
Now, I'm not an education researcher or an educator of any sort. But I am passionate about good STEM education, especially in math. I genuinely feel that math education fails most students, at least here in America. If I'm being generous, this article is a well-intentioned but poorly-executed argument for effective math education strategies. If I'm not being so generous, this article advocates for the status quo in math education that forces students to slog through years of math classes for little discernible benefit. Either way, it's a disappointing article with a poorly-explained thesis.
I wonder this too, I think they might mean university-level as well. For younger audiences, I feel one of the biggest problems for most people to understand math is they don't understand why any of it is relevant. If educators can make it seem more like teaching general problem solving abilities, that will likely improve the overall acceptance and lead to better overall math skills as a result.
As a specific example, our high-school math curriculum taught a lot of calculus, but framed it incorrectly as being a useful tool that people would use. Eg as if a business man would write down an equation for their revenue based on inputs, and then take the derivative to compute the maximum. I'm assuming they told students this to try and get them motivated, but it clearly was a lie since everybody knows you could just plot a graph and look at it to find the maximum. If they instead were honest that the point of learning calculus was to help with understanding more advanced concepts in math/engineering/science, while also being a valuable learning tool for general problem solving, I think that would have been a better result.
One day at FedEx the BoD (board of directors) was concerned about the future of the company and as part of that wanted an estimate of the likely growth of the company.
In the offices there were several efforts, free-hand, wishes, hopes, guesses, what the marketing/selling people thought, etc., and none of those efforts seemed to be objective or with a foundation or rationality.
We knew the current revenue. We could make an okay estimate of revenue when all the airplanes were full. So, the problem was essentially to interpolate over time between those two numbers.
For the interpolation, how might that go? That is, what, day by day, would be driving the growth? So, notice that each day current customers would be shipping packages, and customers to be would be receiving packages and, thus, learning about FedEx and becoming customers. That is, each day the growth would be directly proportional to (1) the number of current customers creating publicity and (2) the number of customers to be receiving that publicity.
So, for some math, let t be time in days, y(t) the revenue on day t, t = 0 for the present day, and b the revenue when all the planes were full. Then for some constant of proportionality k, we have
y'(t) = k y(t) (b - y(t))
where y'(t) = dy/dt the calculus first derivative of y(t) with respect to t.A little calculus yields the solution.
y(t) = y(0) b exp(bkt) /
( y(0)( exp(bkt) - 1) + b))
Seeing how the growth goes for several values of k, pick one that seems reasonable. Draw the graph and leave it for the BoD.That was a Friday, and the BoD meeting started at 8 AM the next day, Saturday.
First thing at the meeting, two crucial BoD members asked how the graph was drawn. For several hours, no one had an answer. The two members gave up on FedEx, got plane tickets back to Texas, returned to their rented rooms, packed, and as a last chance returned to the BoD meeting. FedEx was about to die.
I did all the work for the graph, the idea, calculus, arithmetic (HP calculator), but didn't know about the BoD meeting. Someone guessed that I did know about the graph, and I got a call and came to the meeting. The two crucial BoD members were grim, standing in the hallway with their bags packed, and their airline tickets in their shirt pockets.
I reproduced a few points on the graph, and FedEx was saved.
So, some math saved a business.
Then, for the arithmetic, some code can be short and, compared with cells in a spreadsheet, easier and with more control over the time steps, e.g., in Rexx with cf for customer fraction:
Say ' ==== Growth ===='
Say ' '
Say ' Customer'
Say ' Year Fraction'
max_years = 5
steps_per_year = 10 * 365
cf = 1 * ( 1 / 100 )
year = 1
k = 1 * ( 1 / 2000 )
Do Forever
Do i = 1 To steps_per_year
cf = cf + k * cf * ( 1 - cf )
End
Say Format(year,9) Format(100*cf,10,2) || '%'
If year = max_years Then Leave
year = year + 1
End
yielding ==== Growth ====
Customer
Year Fraction
1 5.89%
2 27.97%
3 70.66%
4 93.73%
5 98.93%
So, get a 'lazy S curve'. I've since
learned that the curve has a name, the
'logistic curve'. And, right, can also
consider that curve for other cases of
growth, e.g., for a first, rough estimate,
COVID.Adjust some of the constants in the program and can get more output, say, for each month, day, etc. The code above uses 10 steps per day.
For more, someone could use the calculus solution and compare.
In a sense, for the FedEx problem and the assumptions about what was driving the growth, the calculus solution is a smooth version of the somewhat more appropriate discrete time version.
But when I did the calculation at FedEx, my best source of arithmetic was an HP calculator in which case the calculus solution was a lot easier.
Of course, this FedEx calculation was just one example and there are many others.
My view from 10,000 feet up is that in business, at times some math can be an advantage if not the work of a steady job.
If some math is an advantage, then that advantage tends to go to the owners of the business. If a mathematician wants to get paid for some math they have in mind, maybe they should start a business and be the owner.
For the arithmetic for the calculus solution, in Rexx,
y.0 = ( 1 / 100 )
b = 1
k = ( 1 / 2000 )
Do t = 1 To 5
t1 = t * (10 * 365 )
e1 = RxCalcExp( b * k * t1, 16 )
y.t = ( y.0 * e1 ) / ( y.0 * ( e1 - 1 ) + b )
Say Format(t,9) Format(100*y.t,6,2) || '%'
End
Table below has the values from both the
calculus and the discrete versions: ==== Growth ====
Customer Fraction
Year Calculus Discrete
1 5.90% 5.89%
2 27.99% 27.97%
3 70.68% 70.66%
4 93.73% 93.73%
5 98.93% 98.93%
Lesson: Sometimes in growth problems with
a calculus solution, a discrete version
can give close results.Maybe, we need alternative approaches, to make the topic more interesting.
> Maybe, we need alternative approaches, to make the topic more interesting.
You realize kids only have around a single full time year to learn math, if you add up all 12 school years? They don't have the time you did when you started practicing programming.
Probably not even if you consider that basically half of every school year is review and relearning what some of the students forgot from the previous year. Rich people have the right idea with having private schools and private tutors for everything. We really need to democratize individualized education more. We are getting there somewhat with inclusion of technology based learning but we still aren't really allowing students to reach their full potential.
However, everyone wants shortcuts, specially recent generations with short attention spans
Do your 10k hours conscientiousnessly in a specific domain and you're automatically at a huge advantage in the current market
like most things gladwell made up, it sounds good at first but falls apart the moment you think about it for a second
I often state I don't know anything about math as if there's a python library and a wikipedia page that's usually enough for my purposes, and then use a kind of profane math to do stuff instead of the sacred math that seems mostly to be about arguing and telling people what is impossible. Learn math for real, it's admirable and useful, and maybe someone will hire you to turn their handwavings into something someone wants.
A. To create top flight mathematicians who can push the frontiers of the field forward. Arguably not a whole lot of what we do in K-12 and the first couple of years of college isn't really aimed at this for the most part, since there is such a strong applied math push and the proofs stuff we teach in K-12 is broken.
B. To create people competent enough in math to be engineers and scientists. Most math systems are pretty squarely aimed at this.
C. To create people competent enough to live a life which tangentially touches mathematics (even if they are in a field like most of finance or accounting or whatever, the amount of mathematics they will do is limited). Here, I think we go pretty far off: getting a person just barely through Algebra 2 or trig doesn't serve them well; you'd be better off teaching them first and foremost not to be scared of mathematical reasoning, about general problem solving ("look, you can just hold up the shape and rotate it!" "we can figure out the length of the board with a compass!"), and strengthening their general arithmetic and lower math skills.
I think we need to diversify out from path "B" to do both "A" and "C" better.
* Or the way you can make endless fun puzzles you can solve on a rainy day?
Re: your point: I've said often that I think most math classes should be roughly equal amounts of
* Exploration/play/intuition-building
* Rote practice of problems, facts, specific problem solving or symbolic manipulation techniques.
* Rigor / careful explanation
(The exact balance may shift a bit, from younger students doing the first two a bit more and older students doing the latter a lot more).
I think if you do this better, more of the populace will happily make it past Algebra 2. But still, even so, others will still get stuck in real understanding somewhere between Algebra I and Geometry, and I think we need to decide what to do then so as to best serve those students.
Mathematicians RIP.
Math texbook: Here are worked examples after the chapter. Worked by you. Enjoy your homework!
I'm sorry but one don't exactly come across randomized controlled experiments in teaching very often... not to even mention ones that are well designed... so this isn't saying much.
No op, but I’ve “come across” a lot of education research. By “come across”, I mean I’ve read so much that it makes my eyes bleed.
There is some good research that yields interesting and compelling results. Rare, but out there. Usually by an individual researcher and maybe with a team. Almost never by a school of education of significant size or by (almost?) any specific field in education.
Results in education are challenging to replicate by a different researcher in a slightly different context, and studies are often trivially easy to replicate and come out with a competing/contrary conclusion by controlling a variable that the original researcher mentioned but did not control for (e.g., motivated subjects versus unmotivated subjects).
Additionally, much research in education is not well-designed, or is well-designed but on a relatively meaningless topic. There is a lot of touchy-feely research out there (like the idea that folks can learn math with just problem solving skills), and folks p-hack the hell out of data to support their a priori conclusions. It’s a smart thing to do to maximize funding and/or visibility in academic journals, but it is absolutely irresponsible in the quest for “truth” and knowledge, which one would hope our education researchers would want (n.b.,they largely don’t).
However, there are also many findings that are actually legit. As you say, they're rare, but there are enough of them to paint a surprisingly complete picture when you pull them together.
Discussed at length a couple months ago here: https://news.ycombinator.com/item?id=40348986
The form of the argument is this: there is no direct evidence for X, but there is a mountain of circumstantial evidence supporting "not X", so therefore, almost certainly, "not X."
X = "we can teach students how to solve problems in general, and that will make them good mathematicians able to discover novel solutions irrespective of the content"
I have read the rest of the argument. However, my take upon reading it is that this is just one more contribution in a back-and-forth argument about every aspect that has been studied in math education. Despite the fact that this was published in 2010, the landscape in 2024 very much points to "it's unclear" as the answer to "is [anything] effective?", at least for me, unfortunately.
Interesting. Not sure if you saw the following post from a couple months ago, but if not, you may wish to check it out:
Which cognitive psychology findings are solid that I can use to help students? - https://news.ycombinator.com/item?id=40348986
Usually when there's a replication crisis, people talk about perverse incentives and p-hacking. But there's 2 things I want to mention that people don't talk as much about:
- Lack of adequate theoretical underpinnings.
- In the case of math education, we need to watch out for the differences in what researchers mean by "math proficiency." Is it fluency with tasks, or is it ability to make some progress on problems not similar to worked examples?
That's an interesting point. Ideally students would have both. My impression is that the latter is far less trainable, and the best you can do is go through enough worked examples, spread out so that every problem in the space of expected learning is within a reasonably small distance to some worked example.
I.e., you can increase the number of balls (worked examples with problem-solving experiences) in a student's epsilon-cover (knowledge base), but you can't really increase epsilon itself (the student's generalization ability).
But if you know of any research contradicting that, I'd love to hear about it.
> Lack of adequate theoretical underpinnings.
If you have time, would you mind elaborating a bit more on this?
My impression is that general problem-solving training falls into the category of lack of adequate theoretical underpinnings, but I doubt that's what you mean to refer to with this point.
I simply mean that researcher team A will claim a positive result for method A because their test tested task fluency, while team B will claim a positive result for method B because their test tested ability to wade through new and confusing territory. (btw, I think "generalization ability" is an unhelpful term here. The flip side to task fluency I think more of as debugging, or turning confusing situations into unconfusing situations.)
> If you have time, would you mind elaborating a bit more on this?
I don't know what good theoretical underpinnings for human learning looks like (I'm not a time traveler), but to make an analogy imagine chemistry before the discovery of the periodic table, specifically how off-the-mark both sides of arguments in chemistry must have been back then.
> My impression is that general problem-solving training falls into the category of lack of adequate theoretical underpinnings, but I doubt that's what you mean to refer to with this point.
By the way, I see problem solving as a goal, not as a theory. If your study measures mathematical knowledge without problem solving, your tests will look like standardized tests given to high school students in the USA. The optimal way to teach a class for those tests will then be in the style of "When good teaching leads to bad results" that Alan Schoenfeld wrote about in regards to NYC geometry teachers.
if you can throw a spear and hit the mammoth, that's a problem-solving skill. but when we learned a technique that can calculate the trajectory of the spear, the effect of the timing of jupiter's rising and setting on mars's, and the penetration depth of a baseball into the water, that's math
While some solutions may prove sub-optimal, a refinement process by its very nature emulates a reductionist goal without the confines of abstract contextual dependency or impossible to implement/prove rigorous meanings.
I never understood which approach was superior for practical application, or obfuscation of delusional wishful thinking.
Have a wonderful day, =)
Some people literally memorize answers. Other folks memorize algorithms. Yet other folks memorize general collections of axioms/proofs and key ideas. And perhaps at the very top of this hierarchy is memorizing just generic problem solving strategies/learning strategies.
And while naively we might believe that "understanding is everything". It really isn't. Consider if you are in the middle of a calculus exam and need to evaluate $7 \times 8$ by calculating $7+7+7+7...$ and then proceed to count on your fingers up to 56 because even $7+7$ wasn't memorized. You're almost certainly not going to make it past the first problem on your exam even though you really do understand exactly whats going on .
Similar things are true for software engineering. If you have to stackoverflow every single line of code that you are attempting to write all the way down to each individual print statement and array access it doesn't fucking matter HOW well you understand whats going on/how clear your mental models are. You are simply not going to be a productive/useful person on a team.
At some point in order to be effective in any field you need to eventually just KNOW the field, meaning have memorized shortcuts and paths so that you only spend time working on the "real problem".
To really drive the point home. This is the difference between being "intelligent" versus "experienced".
I'm not sure this counts as memorization. I don't even think you can really "memorize" high level learning and problem solving strategies, even when explained by an expert. You kind of have to re-discover them internally. And then, there are people who "memorized" the explanation and are completely unable to put it into practice because to them it's just a word sequence, instead of an internalized change to the way you perceive and work with problems.
If that isn't memorizing something and making a new habit as a kid then I don't know what memorizing means.
Said another way, the ability to remember to "____" when dealing with a problem of type "___" is what I mean by "memorize".
I think you underestimate the amount of internalized understanding of the "unblock yourself on a difficult problem by solving a simpler version of it" strategy that you possessed or unlocked at learn-time which allowed you to notice its effectiveness. Isn't the sentence more of an easily-retrievable mnemonic for a concept that's much more complicated (than just the information transferred by language) and requires a particular background to recognize how useful it is?
I don’t know how much human brains do in that area vs non-memorization approaches. Ive read about how practicing rational, problem solving in specific domains to bake those heuristics into one’s intuition for faster responses. Most of us have done that, too. Any type of intuitive, problem solving probably involves memorization for that reason.
What was Newton trying to do? What Faraday investigating? Darwin? Smith? Marx? Descartes and so on.
Everything is connected and there is something interesting for everyone, we just don't try.
You can say a politically correct answer like "i don't care how they do it, as long as they get it done" but such a coder will DEFINITELY take months to finish what might take someone else hours.
Such a coder might still be able to suggest new methods to do something better and if there job description was "organizational optimizer" perhaps thats fine but as soon as you also expect software output out of this person you will quickly realize that you take for granted how valuable someone that has fully memorized a bunch of fundamentals up to and including some problem strategies truly is.
You really think there is more value in remembering how to do something in some arbitrary, shitty, programming language than understanding the concept of doing it? With understanding the idea you can do it in any language, at any time, it is just a few seconds away.
I've met too many people who can do a specific thing but actually have no idea what's going on for the GP's logic to hold any water at all.
Memory is a key part of learning. Understanding is great for learning new concepts, but you want to already know a concept. That way lies knowledge and experience.
This is not a counterexample because exams aren't an end goal. The process of filling out exams isn't an activity that provides value to society.
If an exam poorly grades a student who would do great solving actual real-world problems, the exam is wrong. No ifs. No buts. The exam is wrong because it's failing the ultimate goal: school is supposed to increase people's value to society and help figure out where their unique abilities may be of most use.
> Similar things are true for software engineering. If you have to stackoverflow every single line of code that you are attempting to write all the way down to each individual print statement and array access it doesn't fucking matter HOW well you understand whats going on/how clear your mental models are. You are simply not going to be a productive/useful person on a team.
If their mental models are truly so amazing, they'd make a great (systems) architect without having to personally code much.
I used the example of a calculus test and not being able to do addition. But this really could be any example. It could have even been a Wide Receiver failing to read the play thats happening quickly enough despite being physically fit enough to execute the right play in hindsight.
>Re: they'd make a great (systems) architect...
But you wouldn't hire them as a programmer. My sentence was biased in the sense that "team" meant "team of software engineers". You would hire them for a different job sure.
Also good mental model here just means "Always knowing and being able to clearly articulate what I need to accomplish next to write my code". It doesn't even mean they are good at designing systems but lets go with that example anyways below:
The Architect version of this is that they perhaps have perfectly clear mental models of exactly how to code (memorizing very obscure language shortcuts and syntactic sugar and writing very clear code when they know what to build) but they cannot for the love of god think critically about what a design should be BEFORE they implement it far enough to reach a major issue.
And you would rightly say "well I would never hire that guy as an architect but I might have hired them as a programmer thats led by more senior folks". At the end of the day you are only hiring people for the parts of their mental models that are useful.
And the ability to clearly recall facts about that their domain is basically the fundamental detail here.
I would probably not make a developer who had great mental models but lacked coding chops my first hire. Nor the programmer that could make code do amazing things but can not grasp the domain model. I would, however, probably consider them(the mental model one) the 100th to clean up backlogged bug fixes, and the code whiz to implement the more technically difficult backend niche feature/optimization. As much as it pains me to say it, github copilot chat works surprisingly well IF you can give it a clear concise description of the model and expectations. Then someone with an excellent mental model can create the smaller lego pieces and put it together, minimal coding required. Not only for the popular languages, I play with it from time to time using clojure.
Knowing a topic includes instant recall of a key body of knowledge.
CAS and automated tests wins again.
A robosurgeon tech that knows to stop and read the docs and write test assertions may have more total impact.
The field is probably onto post-AES, PQ algos where Galois Theory is less relevant; but back then, it seemed like everyone needed to learn Galois Theory, which is or isn't prerequisite to future study.
The problem-solving skills are what's still useful.
Perhaps problem-solving skills cannot be developed without such rote exercises; and perhaps the content of such rote exercises is not relevant to predicting career success.
I think an example closer to the above posts would be: If I needed cpr or defibrillation, I would much prefer a paramedic be next to me and make that call and performance than a med student or a defibrillator manufacture's electrical engineer.
I certainly don't remember hearing that!
Yes, there is a "habitus" to mastery. It becomes you, or you become it, so to speak.
But pedagogically speaking, I think what people miss is that you can't really use or think about something you don't remember.
Expertise is lossy intuitive reasoning. It's pattern recognition based on practice and experience. Then there is logical reasoning based on memorized facts, which is a fallback mechanism people use when they don't have the necessary skills. It usually fails, because it's inefficient, it doesn't scale, and it doesn't generalize.
Sometimes memorization is necessary, but it's often not the actual point. When kids are asked to memorize the multiplication table, they are not really supposed to memorize it. They are supposed to build a mental model for multiplying numbers without resorting to first principles or memorized answers. Then if your model can calculate 7 * 8, you can also use it to calculate 7e10 * 8e11, even if you haven't memorized that specific fact.
This is arguably another form of memorization. Magnus Carlson is the best Chess player in the world because he memorizes everything without effort.
But you can break this into a different problem knowing that 2^3 = 8, and doing 7*2*2*2.
This isn't as fast but is in a way more useful because while 7*8 is fairly easy to remember you're not going to remember 17*8 etc but you can problem solve it fairly quick.
There are other ways of seeing the multiplication table as well. For example 9 times something can be thought of as 9*x = 10*x-x.
I never learnt these, but simply realised over time that there are different approaches to doing calculations.
Doing that multiplication all the way through is super slow. When they said "can't" they meant in an effective sense, since they did mention repeated addition as an option. And that's not an effective way to get there.
> There are other ways of seeing the multiplication table as well. For example 9 times something can be thought of as 9*x = 10*x-x.
Yes, you can do that one. But that's just about the only fast trick there is.
I dunno about that. For division, anyway, there's a bunch of fast tricks that give you a decent approximation (i.e. decent precision, maybe to the nearest integer)
Someone recently was surprised that I worked out the VAT (Value Added Tax, 15%) on a very large number in a few seconds. It's because its 10% of the number plus `(10% of the number)/2`.
It's easy to get 10% of any number. It's easy to halve any number. It's a fast trick because there's two easy operations.
There's a bunch of similar "tricks": 1%, 10%, 25% and 50% are fast to calculate in your head (at most 2 easy operations, like `(half of half of N)`). Then you either add or subtract N. Or you multiply N by 2.
At most three easy operations gives you 1%, 2%, 4%, 5%, 10%, 11%, 12%, 14%, 15%, 20%, 21%, 24%, etc
To someone who doesn't know how you are getting the answer it might seem like you are a human calculator because you get so many of those quickly, and they don't see the ones you don't do in 3 easy operations (say, 13%, which is 10% + 1% + (1% * 2)).
IOW, it looks like a very impressive trick, but it isn't.
Did you not see the neighbor comment where I made it extra clear I'm talking about times tables in particular?
There are tons of math tricks! But the multiplication table of the numbers between 1 and 10 is mostly rote.
Also, learning multiplication with numbers higher than 10 still relies on knowing the multiplication table. 17*8 is 7*8=56, hold the 5, 1*8 + 5 = 13, so 136.
You've actually just proved my point - you used a method of breaking down the problem into a different problem and then solving it rather than simply memorising.
If you give the same question to multiple people there will be numerous ways different people use to go about solving it.
As an example, I might solve this by doing
20*8 = 160 3*8 = 24 160 - 24 = 136
Or 10*8 = 80 7*8 = 56 80+56 = 136
And I might apply different tools like the one I originally mentioned within these calculations. I know that 80+20 is 100 and so "borrow" 20 from 56, so that I can easily add 100 and 36 together.
These ways of calculating happen in your mind very quickly if this is how you get used to calculating.
Interestingly, I do those less efficiently:
17 * 8
= (10 * 8) + (7 * 8)
= (80) + (56)
= (80) + (50 + 6)
= 130 + 6
I think the reason I do it this way is because I get an approximation sooner when the numbers are very large i.e. I get the most significant digit first, and can stop calculating when I get the precision I require.*In sports and other physical activities, you don't memorize the right moves. You practice them until you can do them automatically. The same approach also works with cognitive activities.
Edit: I should also note that it's pretty well known people learn arithmetic as symbol manipulation and not some higher order reasoning. The reason this is pretty well established is that historically, the switch from Roman numerals to Arabic numerals led to a huge flurry of arithmetic activity, because it was so much easier to do arithmetic with the new symbols. If people had learned by subconsciously calculating the underlying linear functions and not through symbolic manipulation, the switch would have been entirely irrelevant. Yet for most mathematicians in Europe at the time, doing 27*3 was much easier than doing XXVII*III.
I never memorized the multiplication table, because I found it boring and unnecessary. When I had to multiply numbers, some answers just appeared automatically, while I could calculate the rest quickly enough. Over time, more and more answers would appear magically, until I no longer had to calculate at all.
Some other things I had to memorize. Those were usually lists of arbitrary names with no apparent logic behind them. And if I didn't need them often enough, they never became more than lists of random facts. For example, I often can't tell the difference between sine and cosine without recalling the memorized definitions.
Or, to give another example, Finnish language has separate words for intercardinal directions (such as northeast). Usually when I need one of them, I have to iterate over the memorized list, until I find the name for the direction I had in mind. Similarly, I had to iterate over the six locative cases in Finnish grammar whenever I needed a name for one of them.
> When I had to multiply numbers, some answers just appeared automatically, while I could calculate the rest quickly enough. Over time, more and more answers would appear magically, until I no longer had to calculate at all.
This is prefectly explained by some results becoming memorized as you see them more and more, and makes no sense if your unconscious mind were computing things. If your brain was computing these results unconsciously because it had learned the function to apply, it should have come up with results automatically for any (small) multiplication. That it didn't, and you had to consciously do the computation for some numbers, is pretty clear proof that you slowly memorized the same multiplication table, but only filled it in gradually.
Overall I'm not advocating for the importance of cramming the multiplication table. I'm just saying that people who want to do mental arithmetic, or even pen-and-paper arithmetic, can only realistically do it if and when they learn the multiplication table by heart. And, that the reason the multiplication table is taught to children is strictly to have them memorize it so that they can do arithmetic without a calculator at realistic speeds.
Then you may be a perfectly adequate programmer. This, what, doubles the length of time it takes to type out the program? Triples? Typing out the program is not what takes the time!
I've just spent a couple of days writing a plugin in a language I don't know. (The system documentation spends two paragraphs explaining how hard it is to solve the problem I solved.) Yes, I had to look up absolutely everything (including basic language syntax – repeatedly), and that was really annoying, but most of my time and effort went into figuring out how to do the thing.
Like, once you learn a programming language, you already know the syntax for 90% of all languages.
open Option Parse Scan;
(maybe embedded --| minus -- name >> (fn arg => ((if ! testing then #2 arg |> Output.writeln else (); #1 #> curry getOpt) arg (implode [])))) -- command_name "supply" >> (op ^)
What does this say?AS for memorizing generic problem solving strategies - I don't think it's about not memorizing, but rather that understanding comes through examples, and if you learn high-level stuff without actually applying it in practice, and experiencing the process, then you haven't actually learned the high-level stuff, you just think so, and will parrot the description without comprehending it.
FWIW I think you in particular are exactly right. I always think of Schopenhauer’s quote, and I think any software engineer might appreciate it: human memory isn’t storing items received from the world in a database, it’s more like folding creases into a napkin so that it naturally tends to fall into that shape in the future. In other words: remembering an event is equivalent to developing the skill of imagining a scene/dataframe that relates to that event.
In specific math terms: math is a collection of intellectual tools building on one another. You can certainly practice the ability to apply tools in new situations, but if you don’t also practice the ability to recall the tools themselves, it’s useless.
We don’t know everything, but we have more evidence than “it’s a black box” - in fact, that’s basically the scholastic / Aristotlean view that was conquered by our friends Bacon, Hume and Kant a few hundred years ago.
I’ve seen up close a few people who could fairly be described as “most creative researchers in the world” (in my field at least) according to metrics such as h-index and Nobel prizes. It always strikes me how essential exceptional memory is to what they do — they have detailed, immediate recall of the problems in their field and, to the extent this recall is no longer present, then they are no longer producing groundbreaking work. Their recall of facts outside the field is often nothing special.
Imagination, creativity, intelligence all seem to rely on memory in order to operate.
Only somebody who has never thought about or studied human cognition would memorize such a thing. ;)
But in all seriousness, memory isn't even memory isn't just memorization. Much of it is attention, some would even say attention is all you need. ;)
In all seriousness though, arguably, reducing the human mind down to a single dimension like "recall" (or attention) while ignoring other dimensions like emotion, creativity and so on is probably good evidence that human cognition is neither simple, nor unidimensional, for some of us humans at least. Ymmv
I guess that's why we don't seem to hire chess players as generals or... really, anything else. Being good at chess — whilst it clearly necessitates a certain level of intelligence — is basically just being good at chess. The cultural image of the great chess player being a deep thinker doesn't seem to line up with the evidence. I find it particularly interesting that, with very rare exception, none of the world's best chess players seem to go on to contribute anything intellectual other than their chess games.
Also, for some, being a ‘social butterfly’ is perfectly possible (with some effort) but is boring. This tends to be true the more into ‘hard things’ you are. Chatting to people about banality isn’t hard, so it isn’t interesting.
I dunno. My experience is that it's true for some fields, such as videogames/sports.
What I've found is that people who have true expertise in a field (excluding videogames/sports) are generally competent in a number of other fields. The characteristics required to become an expert oil painter or an expert in applied mathematics (for example) are focus, concentration and the ability to recognise new patterns as patterns, and then apply them!
IOW, someone who is an actual master in a certain field should easily become at least competent in other things that they try.
Because I find that there's a very wide range among 'well-regarded (by some) public intellectuals.' Some of them say things worth thinking about. Many others, not so much, the only noteworthy thing about them is that they stand on a soapbox.
"[these] results have been replicated in a variety of educationally relevant fields, including mathematics (Sweller & Cooper, 1985)."
Now, I would agree that I wouldn't want to hire a mathematician as a general (on the basis of their being a mathematician), for the same reason that you wouldn't want to hire a chess player as a general (on the basis of their being a chess player).
I just want to emphasize that this applies to math too.
But at this point it's basically vestigial knowledge – like balancing a checking account by hand. Good to understand the underlying principles of personal finance – but almost nobody keeps a checkbook anymore.
I'm not saying everyone needs to know math but its hardly "vestigial knowledge".
Honestly, this is a pretty weird take to see on “Hacker News”. This place sure has changed a lot.
That doesn't mean you won't be rich. It's just some of the lowest hanging fruit are not an option.
I remember a rich man interviewed on TV who said he got his start making money in high school by running gambling games. He understood statistics while the other kids did not, and although the game was fair, he cleaned up regularly.
Take a walk through a Vegas casino, and you'll see legions of people who do not understand statistics and pay a heavy price for that.
At the risk of stating the obvious, and not adding to the conversation, I think we all know that people putting their life savings into slot machines aren't doing so because they don't understand expected value. They may or may not understand that they are going to lose all their money, but they are gambling because they are addicted/have some kind of mental health problem. Knowledge of statistics doesn't really affect things for problem gambling.
As for those putting modest amounts of money into gambling, most of them will tell you that card games/etc. are fun, and are therefore worth it.
Watch people at the slots. Do they look like they're having fun? Not to me.
Personally, I've gambled a few times. Lost money. I don't like losing money, it is not entertaining to me in the slightest.
Tell me about people who play the lottery, picking their "lucky numbers". It's sad.
Or are these "systems" for slots?
The original thread was about how statistics education will not cause people of gambling. Of course people almost always lose money gambling, except for very rare exceptions, but that doesn't really have anything to do with my point that people spending meaningful amounts of money on gambling are addicted. Addicts aren't going to just tell you that they gamble, because they are addicted(maybe some will but not in general).
> Personally, I've gambled a few times. Lost money. I don't like losing money, it is not entertaining to me in the slightest.
Some people could probably say the same thing about video games, but nobody disputes that some people enjoy video games.
We also don't teach car repair, or hunting, or sewing, or cooking much anymore either, not because we don't need those things but because those high-friction tasks have been highly optimized to the point of being background noise.
(commenting on the internet can be fun you know ;-) )
That or everyone else is an idiot, but I've found that mindset is only good for feeling smug about yourself and underestimating people, so let's assume it's not that and try to find something else.
One of my in-laws bought a house in the suburbs. She kept her low-wage job downtown, despite pay being average for her vocation, and she could easily get a job closer to her new home.
So now she has a long commute, and decided to get a petrol car.
Despite knowing very well that petrol is taxed heavily and electricity is cheap here in Norway, petrol cars have significantly higher road tax and congestion charge than EVs here. The distance she needs to commute is well within what even a first-gen Leaf could do during winter, so she had plenty of EV options.
She also knew the job had no parking for employees, so she has to park at a public parking facility, which downtown costs a fortune.
Basic math skills shows that between the petrol, the road tax and congestion charge and the parking, that car is costing her half her daily paycheck each time she goes to work.
Didn't take long after she got the car till she started complaining she was "broke each month".
I mean I've been in 'tech' for ~25 years. The simple fact is that technology is a meta-adaptation whose primary purpose to make life easier and more enjoyable for humans. I'm not kink-shaming math lovers or anything.
98% (I’m being generous) of people can no longer work almost math past early algebra and maybe a handful of finance-related plug-in-the-numbers formulas by age 35 because, assuming they ever learned any, they have never used it, so it’s gone by then. And that state of things seems to be entirely Ok. Like, if they needed it, they’d have used it and the many of them who could once at least kinda work with calculus, or what have you, wouldn’t have lost that skill.
Meanwhile, I’ve not found the “it teaches problem solving skills, that’s why it’s important even if you never use 80% of it outside of school” thing to really hold. Maybe for the kinds of courses math majors take in college, I dunno, but not for the rest. If it does teach any, they don’t seem to generalize well for almost all people who learn them, and the rest, I think that’s more about who they are than that they took some math courses.
Ultimately, it’s not clear to me that if we taught quite a bit less math to most kids and even college students, anything bad would happen.
I think there are probably ways to approach math in primary and secondary school, and maybe also math courses for undergrads who have a small load of math courses anyway, that would temper its evident uselessness quite a bit—namely, a laser-focus on applications past the very earliest grades—but most math majors seem to want math education to go exactly the opposite way. Maybe they’re right and I’m wrong, I dunno.
As a programmer, not. But as a programmer, I use a different kind of math (such as 2s complement arithmetic, boolean logic, floating point math, vectors, graph math, etc.) all the time.
Knowing math has blocked many attempts by salesmen, contractors, bankers, etc., from ripping me off. If I didn't know math, I never would have even realized that my tailfeathers had been plucked. As for "anything bad would happen", bad things probably happened to you that you were not aware of.
An anecdote: years ago, it used to be popular to run 30 minute seminars on TV called (my version) "Get Rich In Real Estate Using Scams". I recall one that bragged about making a quick $10,000. I figured it was a con, and so watched the show carefully, noting each transaction. And yes, it did net a $10,000 score for the person. But how it worked was through a confusing combination of transactions meant to obfuscate what was actually happening. The key in it was getting your mark to accept a bond that would be worth $XXXX in the future while you got the $XXXX today. In essence, it was exploiting the mark's failure to understand the concept of current value vs future value. The beauty (if you could call it that) was there was nothing illegal about this.
With my math knowledge, it stunk from the outset, even though it took me a while to find the dead rat. Just like with my knowledge of physics, when it was posted on HN that electric cars were 90% efficient, that set me off immediately, and sure enough, there was a rat corpse in it. (The actual efficiency is 60% on a good day.) I was shocked at the well-educated people who bought that article hook, line, and stinker.
(The cake topper on that one was the author was a ski instructor!)
My grandparents never passed grade 4 of primary school.
They absolutely *crushed* anybody, including university people with supposedly strong math inclination, in math and solving skills. Basic arith and probably a bare-acquired intuition of some algebra.
They could do everything in their heads, buy things, make deals, and could dance around most people with riddles and stuff like that some were math-related. I remember one of them that around 15 people of later generations were trying to solve (like for a week), and only one did it. (remember, there was large family and friends, I have 6 uncles)
Even those around 80-90 years old still crush it.
No, they were not savants. Other grandparents of that generation were like that.
And their sons could do better than grandsons. I need machines to help me. And I was the #1 in school.
For a small example, ever watch "Shark Tank" on TV? The sharks are constantly throwing out ROI, valuations, percentages, interest rates, and it's clear the sharks understand the math behind it implicitly, and how each of those numbers relates to the other numbers.
With the rapid fire back-and-forth with the acolyte, it's clear they're at a severe disadvantage if they cannot keep up. If the acolyte were to whip out a calculator, it's pretty clear that would be "no deal".
Failure to understand a few basic mathematical principles leads to a lifetime of poor financial decisions, but the underlying math is something a 10 year old can handle – as can anyone with a calculator.
The calculator is just a tool to get the precision needed. If you understand the concepts, you can get a rough idea of what '17%' is and whether that ballpark is acceptable.
You whip out the calculator only when you need the precision.
Outsourcing low-value/high friction tasks is the whole point of technology.