It’s almost time for the annual celebration of the mathematical constant π (pi), observed on March 14 in recognition of the first three significant figures of pi.

Commonly rounded to 3.14, the digits of pi go on forever and don’t appear to have any repeating patterns. The ratio of a circle’s circumference (the distance around it) to its diameter (the distance across it) is always equal to pi.

In 1988, the earliest known official or large-scale celebration of Pi Day occurred when Larry Shaw, a physicist at the San Francisco Exploratorium, encouraged the staff and public to march around the facility while consuming fruit pies.

Celebrate the mathematical constant with activities hosted by NASA and geared for K-12 students and educators, parents, museums, science centers and planetariums. The 10th Annual NASA Pi Day Challenge begins on March 9, 2023. Solve four mathematics problems involving real NASA missions.

Pi-related math challenge resources are also available for educators, as is additional explanatory information for students.