Celebrate Pi Day (3.14), March 14, with a slice of pie.

That's just one way an Idaho math teacher is serving up a way to commemorate Pi Day, this year on a Saturday, paying tribute to the mathematical constant, "π," a symbol used in mathematics to represent the ratio of a circle's circumference to its diameter.

"It allows me one day,” Julianne Russell, a math teacher at St. Joe's in Boise, told KTVB. “We can do something fun in class, they're excited not to have homework, and they get pie at lunch."

Students at the Catholic school draw pi, eat pie, and recite as many digits as they can as part of a contest in which the top three winners get to "pie" someone in the face.

Akira Haraguchi, a retired Japanese engineer, holds the unofficial record of digits of pi memorized at 111,701 digits, though the Guinness World Record is held by Rajveer Meena in India in 2015 with 70,000 digits recited.

The first large-scale celebration was organized by Larry Shaw at the San Francisco Exploratorium, where he worked as a physicist. In 2009, Congress supported the designation of Pi Day.

Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts, started a tradition a few years ago of sending out acceptance letters on Pi Day.

Princeton, N.J., hosts several celebrations of Pi Day and Albert Einstein's birthday, which also happens to be March 14, in the city where he worked for more than 20 years at the Institute for Advanced Study. In addition to pie eating and recitation contests, the city hosts an Einstein look-alike contest.

And in Ocean City, N.J., you can sign up for a 5K run that is, you guessed it, 3.14 miles.

Just like many other holidays, companies have cashed in and offered deals on the special day. In the past, Whole Foods, Boston Market and Pillsbury have participated.

How many digits of pi can you memorize?

Here is what 100 digits of pi looks like: 3 . 1 4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4 3 3 8 3 2 7 9 5 0 2 8 8 4 1 9 7 1 6 9 3 9 9 3 7 5 1 0 5 8 2 0 9 7 4 9 4 4 5 9 2 3 0 7 8 1 6 4 0 6 2 8 6 2 0 8 9 9 8 6 2 8 0 3 4 8 2 5 3 4 2 1 1 7 0 6 7 9