3.14 are the starting numbers of Pi, and March 14 (3/14) is annual Pi day. Pi is a mathematical constant defined as the ratio of a circle’s circumference to its diameter. The importance of pi has been known for almost 4000 years, since the time of Babylonians, who gave pi a value of 3. There are also ancient records of Egyptians, Archimedes of Syracuse, and Zu Chongzi approximating the value of pi. The greek letter π began to be used in the 1700s to represent pi in mathematical formulae and equations. Over time, mathematicians have searched for more digits of the infinite series of pi through various methods. Currently, there are 2.7 trillion known digits of pi. How many numbers of Pi do you know?