I have a thing for memorising strings of numbers. I’ve committed numerous card/account/phone numbers to memory, and that’s useful as it saves having to check every time the number is needed for something. But recently I embarked on an exercise in numerical memorisation which has no practical application whatsoever.

I’ve read about people memorising so-and-so digits of pi and it always struck me as one of those signature nerd things to do. I guess that’s what appealed to me, in the end. I wanted to be one of those nerds. Plus, memorising numbers is just fun, and I wanted to challenge myself. So, a few months I added a card to Anki that had “recite pi” on the front and 3.14159265358 on the back. I used the pi command to get the digits, and I plan on stopping when I reach the end of the default number of decimal places printed (since the precision determines the digits anyway, I can’t exactly increase it now).

I can’t remember what I did to start with, but I’ve fallen into a pattern of learning 4 new digits at a time, appending them to the rest of the digits I already know. I highlight the newly-added digits in bold so I know which ones I need to be committing ot memory. This technique has had an interesting consequence.

The more digits I memorise, the easier it seems to get to memorise new ones. However, I’ve discovered that although I remember the sets of 4 digits that make up the entire number easily, I don’t necessarily remember what order those sets come in. To solve this problem, I’ve started giving myself hints as I recite, rather like I give myself hints when playing music on the piano from memory. Here’s an example.

At the time of writing, I can recite up to the following point almost glitch-free: 3.141592653589793238462643383279502884197169399375

Since repeated numbers kind of stand out, I used the repetition of the 9 as cue - a musical analogy is the “pickup point”, which every musician who’s played from memory will know about. After that point, though, I kind of got a bit lost. I knew the next 4 sets of 4 digits, but I couldn’t remember the order. That’s when I noticed a pattern. The sets are actually in ascending order of their first digit: 1058 2097 4944 5932

As soon as I noticed that, I had no trouble remembering them. The final set of 4, however, caused me a little trouble. I had a simliar problem with the set “9375” earlier on - I knew what the digits were, but I couldn’t remember their order. Eventually, by forcing myself to recall the order of the first two digits, I was able to remember the entire set. This is also analogous to memorising music, where sometimes all it takes to memorise a tricky passage is forcing yourself to remember a small portion of it by making notes on the music to draw it to your attention, then practising it over and over again.

While memorising pi is a completely pointless endeavour, it’s strangely enjoyable to recite - even relaxing. And I can’t help but feel a silly sense of achievement when I realise I can recite pi to (at the time of writing) 68 places.