menu   Home Answers Math Games Free Resources Contact Me  

Pi Day is on March 14! Do you know why?



Mathematicians love to celebrate anything related to math; consequently, Pi Day was invented by some anonymous mathematician.  It is observed every year on March 14th because if this date is written in a month - day format, we get 3-14 which is similar to 3.14, the estimate we use when working with Pi.

The symbol for Pi (π) comes from the 16th letter of the Greek alphabet which is written as “π”.  When used in mathematics, this symbol stands for a constant which is the ratio of a circle’s circumference to its diameter.  This is approximately 3.14159.  Remember using the formula C = π d in high school ? This formula is used because the circumference of a circle is about three times the diameter.

We classify Pi as an irrational number because it cannot be written as a simple fraction. The decimal goes on and on forever without ending or repeating any numbers. In other words, it is infinite.  While only a few digits are needed for typical math calculations (we usually use 3.14), mathematicians (not me) have calculated Pi to over one trillion digits beyond its decimal point. Pi’s unlimited nature makes it a fun challenge to memorize, but I doubt if anyone has memorized a trillion digits!  Now there is a great bonus assignment for some math teacher to try! 


Since Pi Day gives math people a reason to celebrate, let's have some fun with Pi.  On the left you will see a pumpkin "Pi" (π).  Could it have been made by a mathematician?  On the right, is some "pi" in the sky! I wonder if the person flying the airplane is a pilot?


Have a great and glorious "Pi" Day which, in my opinion, 
is just another way to celebrate math.