Pi
I've memorized around 180 for my school's competition. (Yes, I go to a school of geeks




You learn something new everyday! I've always used PI=3.1415729 as an estimate for PI but geometry books say that's 'only' an ninth-order approximation.
3.1415926

Pi seems to be the most popular irrational number to memorize digits from. I've never heard someone who memorized the first 1000 digits of e, or the Euler constant, or the golden section, or the square root of 2...
Maybe we should also start an easier thread for writing digits of rational numbers Then also people who didn't memorize the digits can play without cheating

The first 100 digits of pi are sufficient to calculate within the size of a proton the circumference from the radius of any circle that fits in our universe.
Okay, this has to appeal to chess nerds.
In the spirit of the add-a-word threads, we each add a digit of pi (the circumference of a circle divided by its diameter), and see how far we can get. Wouldn't it be cool if pi were found to be repeating on a chess.com thread! Please only add one digit before someone else does.
3.