How I memorized π to more than 60 places
In high school I memorized pi to 18 places. It was easy; when you’re 15 years old you can achieve any mental feat imaginable. Knowing the number to excessive precision was useful when I was programming games or art projects, and when doing geometry homework, I would take a 10-second doodle break by writing the number out in the margin. Like the home phone number my mom made us memorize when we were kids (408-722-2997), the number’s now burned forever in my brain. 3.14159265358979323.
I never tried memorizing any further, because (a) it seemed pointless, and (b) I figured it was one of those youthful talents lost to the sands of time. But over the past couple months, I have memorized pi to over 60 places. It wasn’t hard to do, and here’s how I did it.
First, of course, I started with the first 18 digits and built on that. Over the years, while reciting the sequence to myself, I’ve developed a bit of a cadence and rhythm in the delivery. It’s not quite a song, but it becomes effortless to recall it the same way I can remember song lyrics. So I tried to continue to do that.
Second, I picked small chunks of digits. I know nobody remembers phone numbers anymore, but I’ve heard that the inventors of phone numbers put the dash in between the groups of numbers to turn it from the challenge of remembering seven (or ten) individual numbers into a simpler task of memorizing two (or three) groups of numbers. For me, groups of six seem to work well, because I can recite the six as di-di-di (pause) di-di-di (pause), and it stays in a 4⁄4 time signature (that’s a musical term; remember that I find it easier if they’re recited according to a rhythm).
Third, I practice at least a couple times a week. I’ll recite it to myself when I’m waiting in line for lunch or stuck in traffic. I can’t yet say that this will lead to permanent recall (in the way that I’m confident I’d remember the first 18 digits even if I didn’t think about them for five years), but I haven’t noticed any dropoff yet.
That’s pretty much it. I have attached some mnemonics to specific sequences, which I’ll describe below, but those feel more like excess mental baggage that my brain has stored away, rather than a recall aid. Or maybe not; I really can’t tell.
Here’s the story of the individual digits:
- 3.14159: everyone knows this.
- 265358: the “65,” “35” part is starting to establish a rhythm.
- 979323: this is two groups of 3-digit palindromes, and the 323 is a Mazda car model, which reminds me of the Mazda 626, which is the car I was in when my dad decided the red traffic light must be broken and proceeded to almost kill me when we got T-boned in the intersection by a car that had the green.
- 846264: again a palindrome inside this sequence, and 264 reminds me of the h.264 codec.
- 338327: so many threes. For the second half, three times nine is 27, and because my brain has accumulated the two threes from the first half, it’s already primed to spit out 27 as the product of 3 x 3 x 3.
- 950288: makes no sense to me (other than that 288 = 2 x 12 x 12, which is cool), but it’s memorable mostly because it’s a nonsense sequence.
- 419716: 419 is the number associated with those I AM HEIR TO THRONE AND NEED YOUR HELP spam mails (it’s some reference to a penal code or something like that), and the 716 forms almost the same shape if you’re dialing it on a phone keypad.
- 939937: this is weird because it has so many nines in it, and when dialed on a keypad it reminds me of a person on a trampoline jumping back and forth and then accidentally flying off it.
- 510582: 510 is an area code in the San Francisco Bay Area, and the 582 starts with the same digit.
- 097494: makes no sense at all. I need to explicitly remember that after the 510 sequence, the next sequence starts with a zero. The 494 is easier to remember than the 097 because it’s a palindrome.
- 459230: this is the most recent sequence I’ve memorized, and I don’t have it down yet. 459 is dangerously close to the palindromic displacement of the old Chevy 454 engine (dangerously because at the moment I can’t easily remember the 9), and 230 is a protective provision in the otherwise awful 1996 Communications Decency Act U.S. legislation.
So that’s actually getting close to 70 places, and as you can see there’s quite a bit of mnemonic baggage that my brain has conjured up on its own. I will probably keep memorizing more digits because it beats watching TV as far as pointless activities go. However, the number of digits memorized at this point is getting into weirdland, so I might take a break from new digits for a while and just stick with the sixty-something as a party trick.