Pi Day

Pi Day is celebrated on March 14, which is written as 3/14. That is because the math number pi starts with 3.14. Pi is used to figure out things about circles. Many schools celebrate with math activities and, of course, eating pie!

What Is Pi

Pi is a special number in math. It tells you the relationship between a circle's width and the distance around it. The number starts as 3.14159 and goes on forever without repeating. Scientists have used computers to figure out trillions of digits of pi. Even though pi goes on forever, you usually only need a few digits for most math problems.

How People Celebrate

Students and teachers love to celebrate Pi Day with fun activities. Many classes have pie-eating contests or bake pies shaped like the pi symbol. Some kids try to memorize as many digits of pi as they can. Math teachers use the day to show how cool math can be. The holiday was first celebrated in 1988 at a science museum in San Francisco.

Fun Facts

• The record for memorizing digits of pi is over 70,000 digits, held by Rajveer Meena of India.
• Pi Day became an official national holiday in the United States in 2009.
• Albert Einstein was born on March 14, which is also Pi Day.

Did You Know?

NASA only needs to use 15 digits of pi to send spacecraft across the solar system with great accuracy.