i 8 sum pi (I Ate Some Pie) Math Keyring

A classic maths joke and perfect for those who have a passion for maths! (And for those who are considering buying this as a gift - the square root of a negative number is "i" aka an imaginary number. 2 to the power 3 is 8 (2 x 2 x 2). "Sigma" is the Greek symbol for "sum" as in add and that cute moustache on the pie is the mathematical symbol for Pi. Here endeth the lesson.