Today is Pi Day; a day when we’re all meant to celebrate the glory of Pi by eating pie. An invented holiday? Never!

To celebrate Pi Day this video answers the question asked by adults and children alike every year: “What is Pi?”

Pi is one of those strange numbers that everyone knows about but hardly anyone uses on a daily basis. It’s an important number though, being a mathematical constant, meaning it’s understood around the world.

There is also a strange fascination with memorizing as many digits of Pi as possible, with the record standing in the tens of thousands. I’ll still to 3.14159 if it’s all the same to you.