Addition is when we put numbers together to see how many we have in total.

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For example, let’s add 3 + 4:

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Start with 3 things. You can imagine 3 apples: 🍎 🍎 🍎

Now add 4 more things: 🍏 🍏 🍏 🍏

When we count all of them together, we get:

🍎 🍎 🍎 🍏 🍏 🍏 🍏 → 1, 2, 3, 4, 5, 6, 7

So, 3 + 4 = 7.

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Sometimes when we add numbers in the ones place, the total is more than 9. When that happens, we can’t put all the numbers in the ones place, so we write down the extra digit in the next column. This is called “carrying the one.”

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For example, if we add 18 + 7, we start with the ones place. 8 plus 7 equals 15. We can only write a single digit in the ones place, so we write 5 and carry the 1 to the tens place. Then we add the tens place: 1 (from 18) plus 0 (from 7) plus the 1 we carried equals 2. So the total is 25.

Carrying the one just means moving the extra ten from the ones column to the tens column.

TIP!

Addition is commutative, meaning it works backwards!

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​1 + 5 = 5 + 1

7 + 18 = 18 + 7

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