Class group

A class group is like a group of friends! Let's say you go to school with a big group of kids, but you all get split up into different classes. Your class becomes your class group. It's the group of kids you'll be spending most of your time with in school.

Similarly, in math, we have something called a class group. It's a group of certain numbers that are all related to each other in a special way. Just like how you and your classmates are related because you all go to the same school, the numbers in a class group are related because they have something in common.

This special thing they have in common is that they all represent the same mathematical concept. For example, let's say we're talking about the concept of "evenness" in math. The class group for this concept would be all the numbers that are even, like 2, 4, 6, 8, and so on.

Just like how you can make new friends in your class group, in math, we can also make new numbers in the class group by combining existing numbers in a certain way. This is kind of like making new friends by introducing yourself and getting to know each other.

So that's what a class group is in math! It's a group of numbers that are related to each other because they represent the same mathematical concept.