Learn the first 100 digits of Pi | Hacker News Reader

Learn the first 100 digits of Pi

pitoletters.awardspace.com

17 pointsanc202017 comments

In a society with nearly ubiquitous access to the internet how valuable is it to memorize raw facts? There are a few anecdotes about Einstein not knowing his phone number and not knowing the number of feet in a mile. His answer was along the lines of questioning why one should memorize something that can easily be looked up.

Personally, I find understanding concepts and composing ideas to be far more valuable. However, I'd be interested in finding out if the memorization of facts somehow exercised/increased the brain's ability to perform more (arguably) meaningful tasks.

1) Its a cool party trick - if you can give someone the 82nd digit of Pi in 8 seconds, they'll probably be impressed because you can't really do that using a conventional method of counting in your head through to that digit of Pi in such a short time.

2) Brain excercise - things like this will probably help keep your brain healthy.

> Personally, I find understanding concepts and composing ideas to be far more valuable.

Me too, they're not mutually exclusive! I very much take the same view about memorizing facts and have a generally poor memory. That's partly why this is cool, I still knew the first 25 digits of Pi effortlessly 2 years after doing this.

You and I go to vastly different parties if that's a cool trick.

I know of at least one place gives out free pie on Pi day if you can recite 100 digits of pi. (For each digit of pi you have memorized you get 1% off)

Say a slice of pie is $3. Pi day comes around once a year. Assume you'll live for 60 more years, getting your free slice of pi every year, and the average inflation adjusted interest rate will be roughly 3%. Then the present value of memorizing the digits of pi will be $83.03.

How long will it take you to memorize? How much are you getting paid hourly now?

Use this to impress your friends by recalling the nth digit of Pi where n < 100

It took me four days I think, 5 words a day, and got me some beer money from my maths teacher.

Only slight relevance to HN because I'd like to think that its a cool way to hack number memory.

It works by sorting the 10 digits 0-9 by number of occurrences in the first 100 digits of Pi, and then associating each digit with the corresponding top n most commonly used letter of the English language (eg. the letter "E" is the most common English letter).

I don't know about English, but in Japanese digits can be pronounced in several ways and many of them are short (e.g. 1 = "hi", "i", "in" or "hito", 2 = "ni", "nin", "fu", "bu", "pu" or "futa", etc), so it's typical to compose a meaningful phrase or sentence to memorize various numbers (e.g. phone numbers).

Remembering pi is a popular game among nerdy kids; I can still recite 200 digits I remembered back in elementary school. Several friends of mime can do 100-800 digits.

For those who can read Japanese, this is one of old ways to remember first 40 digits or so. For 100 digits or more you usually need to come up your own mnemonics:

産医師異国に向こう/産後厄無く/産婦御社に/虫さんざん闇になく/ご礼には早ういくな

Pronounces: さんいしいこくにむこう/さんごやくなく/さんぷみやしろに/むしさんざんやみになく/ごれいにははよういくな

Corresponds to: 3.14159265 / 358979 / 3238462 / 643383279 / 502884197

Roughly translates to: An obstetrician goes abroad. Postpartum is without problem. The new mother is to visit a shrine. Crickets are chirping in darkness. Do not hurry to visit.

reminds me of an old rule of thumb:

http://www.toothpastefordinner.com/031208/how-many-digits-of...

An easier but shorter way:

How I want a drink, alcoholic of course, after the heavy 3 1 4 1 5 9 2 6 5 3 5 chapters involving quantum mechanics. 8 9 7 9

Not as much as 100, but easier to remember.

My math teacher in 8th grade used to have PI in one long print-out across the upper edge of the wall, and I'd usually space out and end up staring at the wall rather than pay attention. 10 years later I know that Algebra was at least 18 digits boring.

I had it memorized to 20 digits after buying a book about Pi. After that, I think I got bored with the topic, but I still remember about that many.

Lemme tell you how many girls this gets me at parties.

How(3) I(1) need(4) a(1) drink(5), alcoholic(9) of(2) course(6), after(5) the(3) heavy(5) lectures(8) involving(9) quantum(7) mechanics(9).

I rather prefer the Cadaeic Cadenza http://www.cadaeic.net/cadenza.htm

I'll try to spend my time on other things.

So, I suppose the method is to learn the 20 5-letter words and the key that goes with it?

The thing is the words don't mean a thing and are not necessarily easy to pronounce. It doesn't really feel like less work than learning the digits straight.

Remembering words is different than remembering digits; mainly because remembering digits is actually remembering words that represent them ("five", for example). Therefore remembering digits would actually require you to remember 100 words instead of the current 20 which you then "decompress" into digits in your head using the simple decoding key.

I did this a while ago, and better, and posted the code:

http://www.jperla.com/blog/2008/03/14/learn-100-digits-of-pi...

Firstly, mapping consonants to digits is hardly original, Derren Brown teaches the method in one of his books, and its one of the techniques used by people who do this seriously. Its also not very space efficient because all of your vowels are counted as whitespace.

Secondly, it would be a lot harder to randomly access the nth digit using your conventional method because you would also need to be counting the consonants as you go along through the sequence, rather than just +5 for every word.

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