## Thursday, March 14, 2013

### It's Pi Day in the Math World

Pi Day is observed on March 14th because if we write this date in a month/day format, we get 3-14 which is the like 3.14, the estimate we use when working with Pi.

The symbol for Pi 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 ?  Now you know why this formula is used to find the circumference of a circle.

We classify Pi as an irrational number because it cannot be written as a simple fraction. The decimal goes on forever without repeating or ending. 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!

For right now, let's have some fun with Pi.  On the left you will see a pumpkin "Pi", and on the right is an Apple "Pi".  And below is what happens when you eat too much of a good thing.