There's no math involved. Knowing the numbers one to nine is all that's needed, and you just need to understand that they are discrete symbols. You don't really need to know the order they go in, even.
Go to
The Daily Sudoku and grab one of their easy puzzles.
Grab a sharp pencil with a decent amount of eraser left, and take a look at a guide to solving.
wikipedia has a fairly decent one. I use the "marking up" method.
There are also some online versions that aren't too bad, with varying difficulty levels and various mark-up strategies.