Hacker News Reader

Comment by roel_v | Hacker News Reader

"Math anxiety affects not only test taking and grades but also self-esteem and everyday computational skills. (How many gallons of paint for two coats of your living room? Can you convert a double-layer cake recipe into a triple-layer?)"

Is this really a thing? Are there adults (except for those in the < 2nd std dev range, who are near-but-not-quite-at mental disability-level) who cannot calculate the amount of paint needed to paint a room?

View on HN

I wouldn't necessarily chalk it up to intelligence. I'm finishing a masters in statistics at the moment, quite a lot of math involved, and I'm mostly doing fine, however when I started the program after not having seen any mathematics in about a decade, I hardly remembered the difference between the circumference and the area of a circle. Now, calculating the amount of paint needed to paint a room might seem like more of a life skill than a math skill, but for some people it just doesn't come up, and when they do suddenly need math for something, they're not likely to trust whatever basic arithmetic they do think they still know.

For some people who are weak at math, it even becomes a badge of honor: "yeah, um, sure, we could calculate how we want to split the bill, but do we really want to be such nerds about it?"

Studies abound, too, showing that even grade school maths teachers often eff up when quizzed on pre-algebra.

What? Yes, of course it's a thing. I meet people like that every day.

A better example of following the rules without understanding would be percentages. Many people could tell you what buttons they push to answer "What is 37% of 240?" But many people would be lost if you asked them "What is 84 as a percentage of 270?"

Or "This product now costs £230. It has had a 20% discount applied. How much did it used to cost, before the discount?"

I think that "learning to regurgitate" information is partially to blame for these type of scenarios. Kids are encouraged to "do past-papers" and other such practice-based learning techniques; while these techniques may be a component of establishing knowledge they are most certainly not a singular solution. A person who has only done past-papers only knows how to be a parrot, and a parrot can't make the creative leap from "% of X" to "X over Y as %."

People I went to school could definitely work out the paint or percentage problems, but for a really good majority of them: only because they faced those exact questions in exams/tests.

Yes. Not among engineers, of course, but among the general population? Yes.

I know what you're getting at but to be fair that probably is a slightly trickier question than it seems. You need to factor in how absorbent the walls are (are you using unfinished drywall?), what colour the walls currently are (Is it very different to the paint? You'll probably need multiple coats.), what's the brand of paint you're using (I've seen different brands range between 350 - 450 sqft / gallon).

The math version of the question would say "This little can of paint can give a single coat to 5 square metres of wall. How many cans would you need to give two coats to a room that is 4 metres by 3 metres by 2.5 metres?"

A number of people can't do this.

Reply on news.ycombinator.com