For math enthusiasts around the world, March 14 (3-14) is Pi Day, honoring the number pi, which is the ratio of circumference to diameter of a circle.

Pi number (3.14159265358979323846264338327950288…) has captivated imaginations for thousands of years.

Approximately 3.14, pi number has its own holiday on March 14, which also happens to be Albert Einstein’s birthday.

You won’t get off school for Pi Day, but you might be doing something special in school on Friday (the last weekday before Pi Day).

Mathematicians, teachers, museum directors, math students of all ages and other aficionados celebrate the number with pi recitations, pie-baking, pie-eating contests and math-related activities.

March 14 is Pi Day, honoring the number pi

Pi Day has gained popularity worldwide every year during the last decade as enthusiasm has spread on the Web, said David Blatner, author of The Joy of Pi.

One of the oldest, if not the first, established Pi Day celebrations is at the Exploratorium in San Francisco, California, which boasts 22 years of pi mayhem. The day is even recognized by the U.S. government: Last March, the U.S. House of Representatives passed a resolution supporting Pi Day and encouraging schools to teach children about the number.