Pi Day, officially recognized in the U.S. in 2009, serves as a day to grab pizza and pie deals at food chains nationwide.

Math nerds and dessert enthusiasts unite to celebrate Pi Day every March 14, the date that represents the first three digits of the mathematical constant pi.

Celebrate the mathematical constant with free food. You know it makes sense.

Representing the ratio of a circle’s circumference to its diameter, pi is approximately equal to 3.14159 — but its digits go ...