Here is how some math classes celebrate and don’t miss the pi song — it will hang in your brain for sure! Students participated in special PI Day activities, celebrated the day by singing PI Day songs, and (of course) the traditional eating of the pies.

At 3.14 (3 minutes 14 seconds) David Letterman learns what pi means! Daniel Tammet is an amazing math genius who memorised pi to 20,000 places. Is he the world’s greatest math prodigy? He is an amazing mathematics savant or maths prodigy.

Think I’ll go have another piece of pie now just to help celebrate the day.