A numbering scheme is like giving things special names or numbers so we can tell them apart.
For example, you know how your mom or dad may have given each of your socks a special number so that they always know which one goes with which? That's a type of numbering scheme!
In real life, numbering schemes are used for lots of things, like for books in a library or for students in a school. It can even be used for big things like houses or buildings. Having a numbering scheme makes it easier to keep track of all those things and to find them when we need them.
Sometimes numbering schemes can be really complicated, with lots and lots of numbers and letters, and other times they can be really simple like 1, 2, 3. But the idea is always the same - to give everything a special name or number so we can keep it organized and find it when we need it.