National Pi Day: Math lovers celebrate illustrious ratio (Video)

Math lovers have likely had Thursday circled on their calendars for some time - the day they get to celebrate one of the world's most famous numbers.

March 14, or as written 3/14, is National Pi Day. Pi, of course, is the symbol used to represent the ratio of the circumference of a circle to its diameter.

The exact Pi is millions of digits long, but most know it at the very least as 3.14, or many can also extend it to 3.1415926...and so on.

For dessert lovers, though, National Pi Day is not only a letdown, it's a bit of a homophonic misnomer. According to the American Pie Council, National Pie Day was Jan. 23.