Did you notice Ms. Adrianna Arrieta and Ms. Lexi Quintero selling an assortment of delicious pies, from cherry to blueberry to key lime, pumpkin, apple, and even sweet potato on March 14?

Or, did you see some of your favorite teachers allow themselves to get “pied” in the face by students?

Just what is going on?

Pi Day is an annual celebration of the mathematical constant π which is observed March 14 since 3, 1, and 4 are the first three significant figures of π.

Founded in 1988 by Larry Shaw, an employee of the San Francisco, California science museum, the Exploratorium, Shaw is also an American artist and physicist.

The first Pi Day was celebrated by marching in circles with colleagues and snacking on different kinds of pie. The celebration of Pi Day began on March 14, 1988, at the San Francisco Exploratorium, where physicist Larry Shaw organized a celebration to make mathematics more relatable and fun (cnn.com).

The famous number is a constant, meaning it basically never ends.

“Pi was originally discovered as the constant equal to the ratio of the circumference of a circle to its diameter. The number has been calculated to over one trillion digits beyond its decimal point. Calculations can continue infinitely without repetition or pattern, because Pi is an irrational number.” (biophysics.org).

The record for the most numbers calculated in pi is 100 trillion digits. The number is generally recognized as 3.14 and used in mathematics. The Pi Day celebrations include eating pie, playing who can name the most digits in pi, etc. Pi Day is a national U.S holiday declared by Congress March 12, 2009.

The π symbol that we use in math to represent pi was first used by the Swiss mathematician, physicist, and astronomer Leonard Euler in the year 1737.

Before Euler popularized using the Greek symbol π to represent the ratio of a circle’s circumference to its diameter, the value was known as Archimedes’ constant.” (mashupmath.com).

A fun fact about Pi Day is that Albert Einstein’s birthday takes place on the same day.