When you count to 20, you start at 1 (or zero) and count on until you reach 20. Each number is one more than the last. When you count back from 20, you start at 20 and count back until you reach 1 (or ...

Take this quiz to see how much you know about this topic already, then work through the guide and see if you can beat your score. Here are some different ways of showing 10. There are 10 fingers on ...