”Pi Day” will be celebrated in many countries on March 14. Pi (Greek letter “π”) is the name of a constant number in mathematics that represents the relationship between a circle’s diameter (its width) and its circumference (the distance around the circle). The value of the number is 3.1415926535… (and its digits go on forever). Over two trillion digits of pi after its decimal point have been calculated. Since March 14 is written as 3/14 in some countries, this day is celebrated as Pi Day. This year’s Pi Day is even more special as the first 5 digits make up the date 3/14/15. Well, if you take the first 10 digits, you’ll have a very special Pi second – 3/14/15 9:26:53. Many people eat and gift food in the shape of a circle (pizza and pies) to celebrate the number. Albert Einstein, one of the world’s greatest scientists, was born on Pi Day. The mirror image of “3.14” spells “PIE” (image). Here are 3 fun videos about pi.

### Did you know?

The first 144 digits of pi add up to 666, and 144 = (6+6) x (6+6).

The sum of the squares of the first seven prime numbers also equals 666: (2X2) + (3X3) + (5X5) + (7X7) + (11X11) + (13X13) + (17X17) = 666.

*Image Credits: http://www.piday.org/ for the Pi Day t-shirt*

*Sources: http://www.piday.org/, facts.randomhistory.com*