Dear Number Classifiers,

Humans make sense of the world by classifying it. We put like things in one heap and different things in another. We do the same thing with numbers. There are endless ways to classify numbers, but mathematicians have agreed on a few ways that are most useful. You’ve already learned how to classify numbers as odd and even. Yesterday we talked about classifying numbers by their divisibility. Today we’re going to talk about classifying numbers as prime or composite (or neither!).

Prime numbers are an interesting topic, and they’re important to our everyday lives. We won’t quite get into cryptography today, but you have prime numbers to thank for keeping your secrets secure in the digital world. Mostly, we’ll think and talk about the strange but illuminating nature of prime numbers. Their charm might just convince you that there’s some kind of logic lurking behind the universe’s deepest mysteries.

Happy Classifying,

Mr. Heimbuck