For those of you who may not know, tomorrow is Pi Day. Pi is the irrational ratio of a circles circumference to its diameter, frequently truncated to 3.14, corresponding to the date of March 14th, falling this year on a Saturday. It is traditional to celebrate Pi Day with a pie of your choosing and perhaps a math problem or two.

The value was first adopted to its now popular representation of the greek letter “pi” by William Jones in 1707. The term comes from the greek word for “perimeter” of which pi is the first letter. Currently, Pi is known out to 1,241,100,000,000 decimals, with effort being taken to calculate further out.