# National Pi Day Challenge to an 11-Year-Old

One of my 11-year-old daughter’s uncles challenged her to do a writeup for National Pi Day March 14, 2014.  After reading online about Pi, she sat down and wrote this for him:

Pi is the ratio of the circumference of a circle to the diameter of the circle. The i told pi to “be rational” because pi is not a rational number. A rational number is any number that can be written as a wonderful fraction in which the numerator and denominator must be whole numbers. Another reason why pi is not rational is because it is an infinite number.  An infinite number cannot be written as a simple fraction. Therefore pi (3.14) is not rational.

Pi told the i to “get real” because i stands for an imaginary number.  When you square an imaginary number the result is a negative number. However, when you square a positive number you always get a positive (or zero) result. When you square i the result is -1.  Consequently, i equals the square root of -1. An imaginary number cannot be written as a rational or finite number. Therefore i is not real.

In the picture i told pi to be rational because pi is not rational .  Pi told i to get real because i stands for an imaginary number (not real).  Therefore you have the pot calling the kettle black.;)