ELI5: Explain Like I'm 5

Robinson arithmetic

Okay kiddo, there is a type of math called Robinson Arithmetic. It was created by a man named Robinson, just like how you might make something and give it your own name.

Robinson Arithmetic is a way to do math using only a few simple rules. It’s like building with blocks, but instead of building towers or castles, you are solving math problems.

The rules of Robinson Arithmetic are very basic. You can add, subtract, multiply, and divide just like you do in regular math. The only difference is that in Robinson Arithmetic, you can only work with numbers that we call natural numbers.

Natural numbers are the counting numbers, like 1, 2, 3, 4, 5 and so on. But you can’t use any numbers that are less than 1, and you can’t use any fractions or decimals.

Robinson Arithmetic is useful because it can show us how other types of math work without being too complicated. Sometimes, mathematicians use Robinson Arithmetic to understand how things work in more complex types of math.

Does that make sense to you, little one?