How to remember 100 digits of Pi, easily

Jan 19, 2023 · Last updated: Apr 1, 2023 ·

Categories: pi, recreational-math, mnemonic

I know, this is a completely worthless thing to memorize. Even NASA uses a mere 15 digits of Pi for their highest precision calculations, and according to them, just 38 digits of Pi are sufficient to calculate the circumference of the entire observable universe to an accuracy equal to the diameter of a hydrogen atom. But hear me out, this is a trick that's worth learning if you want to impress your friends, especially considering how easy it is to learn!

The technique is a standard method used by professional memory champions. So if you learn it for this trick, you can use it for many other use cases, like memorizing phone numbers and even the order of a shuffled deck of cards. It's called "major system". This allows you to map each digit into a distinct sound and construct mnemonics that are easy to remember. See the table below:

Numeral	Associated letters
1	t, d
2	n
3	m
4	r
5	l
6	j, sh, ch, soft g
7	k, hard g, hard c
8	f, v, ph
9	p, b
0	z, s, soft c

Let's look at an example. Say you want to remember the number 42. Since it maps to [r, n], you can choose any word that has these consonant sounds like rain, run, or ruin. Similarly, 620 could be jeans, Jonas, or chains. An important property of this system is that although a number can be converted into many words, a word can be translated only into a single number.

Now let's get to the good stuff. Try to remember the following sentence:

My turtle Pancho will, my love, pick up my new mover, Ginger.

Done? Congratulations, you now know the first twenty-four digits of Pi! Here's how it works. If you map the consonant sounds in that sentence back to the digits from the table, you get the following:

My turtle Pancho will, my love, pick up my new mover, Ginger.
3  1415   926    5     3  58    97   9  3  2   384    6264

Let's go a bit further. Add these sentences to the previous one and you've got the first sixty digits.

My movie monkey plays in a favorite bucket.
3  38    327    950   2    8841     971

Ship my puppy Michael to Sullivan’s backrubber.
69   3  99    375     1  05820      97494

Finally, let's crank it up to a hundred digits.

A really open music video cheers Jenny F. Jones.
  45     92   307   81    640    62    8  620

Have a baby fish knife so Marvin will marinate the goosechick.
8      99   86   28    0  3482   5    3421     1   7067

Here are all the sentences written together:

My turtle Pancho will, my love, pick up my new mover, Ginger. My movie monkey plays in a favorite bucket. Ship my puppy Michael to Sullivan’s backrubber. A really open music video cheers Jenny F. Jones. Have a baby fish knife so Marvin will marinate the goosechick.

How to remember 100 digits of Pi, easily

Further reading