Today is National Pi Day!

It’s celebrated every year on March 14 — 3-14, are the first few digits of Pi

“‘Anyone want to try a piece of my strawberry pie,’ the President asked those at adjacent tables during a stop for lunch at Kozy Corners restaurant in Oak Harbor, Ohio. A young boy said yes and came over for a big bite of pie.” (Official White House Photo by Pete Souza)

It’s the ratio of a circle’s circumference, to its diameter. The exact number goes on and on, without stopping or repeating.

Competitions take place around the world to see how far a person can memorize and recite “pi”.

Computers have only managed to calculate Pi to its two-quadrillionth digit.

Many also use the day as an excuse to buy insane amounts of pie — of the baked variety.

Here are some of our favorite Pi Day tweets!

How do you celebrate Pi Day? Duh! By eating one of these Chicago pies. bit.ly/Z6nUZt—
RedEye Chicago (@redeyechicago) March 14, 2013

I started a @spotify playlist for Pi Day. If you have any songs to add, please tweet and I'm happy to try. spoti.fi/ZqHMWr—
Scott Kleinberg (@scottkleinberg) March 14, 2013

Celebrate Pi Day tonight with this 10-minute chocolate cream pie from #FNMag: bit.ly/Yu6W4b .—
  (@FoodNetwork) March 14, 2013

Happy Pi Day! http://t.co/8MTJAtpwzk—
  (@MLB) March 14, 2013

Happy Pi Day! flic.kr/p/dH3LAX—
The White House (@whitehouse) March 14, 2013