At its heart, addition is simply about combining things. It’s the process of taking two or more groups of items and putting them together to see how many you have in total. Think of it like gathering apples. If you have a few in one basket and a few in another, addition helps you figure out the total number of apples you have without having to count them all from scratch.

We use addition every day, often without even thinking about it. When you're at the store and put a carton of eggs and a loaf of bread in your basket, you're mentally adding the items. If you score 10 points in a game and then score another 5, you add them together to find your new total.

Let's stick with the grocery store. Imagine you already have two oranges in your cart. You decide you need more, so you grab three more oranges. By putting the new oranges with the ones you already had, you're performing addition. You combined a group of two with a group of three to get a new, larger group.

Writing addition down helps us keep track of the numbers we're working with. We use a special symbol, the plus sign (+), to show that we are adding. The result of an addition problem is called the sum, and we use the equals sign (=) to show it.

Sometimes it’s easier to understand addition when you can see it. We can represent numbers with objects or drawings. For the problem above, we can draw two objects, then draw three more, and finally count them all up.

This visual shows that combining a group of two with a group of three gives us a total of five. This is the fundamental idea of addition: joining sets together to find out how much you have in all.

Ready to check your understanding?

That's the basic idea behind addition. It’s a building block for almost all other math you’ll ever do.