Monday marks a special day for mathematicians because it’s March 14th (a.k.a. 3-14), otherwise known as International Pi Day.
Pi, not to be confused with the much more appetizing pie, is the ratio of the circumference of a circle to its diameter. The first three digits of the calculation are 3.14 which has made March 14 the official day of Pi.
Math enthusiasts are calling this year’s day “Rounded Pi Day.” You see, when rounding pi to the ten-thousandth (four numbers past the decimal point), which comes out to 3.1416 and matches today’s date — March 14, 2016.
Here are 3.14 cool facts about Pi.