What Is Pi Day?

March 14 marks Pi Dayan annual celebration of the mathematical sign pi. Founded in 1988 by physicist Larry ShawMarch 14 was selected because the numerical date (3.14) represents the first three digits of piand it also happens to be Albert Einstein’s birthday.

The first Pi Day celebration took place at the Exploratorium (Shaw’s place of work)a San Francisco-based interactive science museumand featured a circular parade and the eating of fruit pies. It wasn’t until 2009howeverwhen the U.S. House of Representatives passed legislation to formally recognize Pi Day.

Why all the fuss about pi? The Ancient Greek mathematician Archimedes is most commonly credited with being the first to accurately calculate the estimated value of pi. Since it is an irrationaltranscendental numberit continues on to infinity—the pi-ssibilities are endless! The seemingly never-ending number needs to be abbreviated for problem solvingand the first three digits (3.14) or the fraction 22/7are commonly accepted as accurate estimations.

In mathematicsthis infinite number is crucial because of what it represents in relation to a circle—it’s the constant ratio of a circle’s circumference to its diameter. Pi is also essential to engineeringmaking modern construction possible.

Since the mid-18th century pi has also been represented by the Greek letter π . In factthe word “pi” itself was actually derived from the first letter of the Greek word perimetroswhich means circumference.

In 2015Pi Day fanatics had a special treat. Celebrations took place on 3/14/15 at 9:26:53 a.m.the numerical date and time together representing the first 10 digits of pi3.141592653. In 2025pi was calculated to more than 314 trillion decimal places—and the mathematicians don’t plan on stopping there.

Mathematiciansscientists and teachers hope Pi Day will help increase interest in math and science nationwidethrough instructionmuseum exhibitionspie-eating (or throwing) contests and much more.