Addition is the mathematical operation of combining numbers to find their total. When you add 3 and 5, you get 8. When you add the number of apples in two baskets, you're finding out how many apples you have altogether.

Addition is one of the four basic operations in arithmetic, along with subtraction, multiplication, and division. It's often the first type of math that children learn, starting with counting objects and progressing to adding larger numbers. The plus sign (+) indicates addition: 12 + 7 = 19.

You can add more than two numbers at once. If you're calculating how much money you earned from three different chores (say, $5, $3, and $4), you'd add all three amounts to get your total of $12. The numbers being added are called addends, and the result is called the sum.

Addition appears constantly in everyday life: calculating the total cost at a store, figuring out combined scores in a game, or determining how many days until a special event. Scientists use addition when measuring quantities, builders use it when calculating materials, and cooks use it when scaling recipes.

The word addition can also mean something added to make a whole larger or better, like a new room built onto a house or a valuable addition to a sports team.