Math nerds and dessert enthusiasts unite to celebrate Pi Day every March 14. Since the American way of writing the date is 3/14, it represents the first three digits of the mathematical constant pi. Representing the ratio of a circle’s circumference to its diameter, pi is approximately equal to 3.14159 — but its digits go on forever. 

The holiday was created in 1988 by Larry Shaw, a physicist at the Exploratorium science museum in San Francisco. “He had a very open and expansive view of the world and saw an opportunity with this number, mathematical concept, to invite people into the joy of mathematical learning,” said Sam Sharkland, program director of public programs at the museum, who worked with Shaw before he died in 2017.