According to UNESCO, March 14 is the International Day of Mathematics. It is dedicated to the number Pi (3.14..), which corresponds to the American spelling of this date. The number pi is the circumference of a circle with a diameter of 1 and is probably one of the best-known mathematical constants. To this day, the total number of pi is unknown; the current status is that around 100 trillion decimal places are known. Together, the participants investigate the puzzle of pi and try to represent pi on a calculator with a few decimal places.