Even if math doesn’t rank high on your list of favorite subjects, chances are you still look forward to Pi Day. That’s because though the discussions may begin with Pi — the ratio of the circumference of a circle to its diameter — they invariably end with a piece or two of yummy pie! The event is commemorated on March 14 because though the irrational number (its decimal representation never ends and never repeats) has been calculated to over ten trillion digits, it is widely recognized as 3.14.