Dear Problem Solvers,

My dad always says “There’s more than one way to skin a cat.” That’s an idiom that means there are a lot of different ways to solve a problem. This is especially true in math.

Good math thinkers don’t stop thinking about a problem after they answer it. Instead, they think about their process of answering, wonder if there are any other ways to solve it, and look for rules and patterns that can make solving it easier. It takes a lot of work  to find rules for solving problems, and we have to make sure the rules work all the time, not just some of the time, but that is the work of mathematicians.

Here’s a problem for you:

How many different coin combinations can you use to make $0.87?