You probably have an interest bearing account somewhere. If you never had math above 3rd grade, that is all magic and something you don't understand. You don't have to calculate interest, but you did have to learn about it understand what is happening and why interest matters.

You are on the Internet. That has alot of math way above the 3rd grade. Have you ever had to write down a MAC address? Or an IP address?

I bet there is more higher math in your life then you are giving it credit