Arithmetic Grade Four

Lesson Three: Addition Review

You can add more than two numbers at a time. Take a look at these examples:

2 + 4 + 3 = 9 3 + 2 + 1 + 1 = 7 2 + 1 + 3 + 1 + 2 = 9 2 + 2 + 2 + 2 = 8

Sums can result from adding two numbers or by adding more than two numbers. The result of addition is a sum no matter how many numbers are used in the addition problem producing the sum.

We can also reverse the way we write addition problem. We can place the sum first, like in these examples:

9 = 5 + 4 8 = 2 + 2 + 4 7 = 3 + 2 + 1 + 1 6 = 2 + 1 + 1 + 1 + 1

What is important is that the numbers on one side of the equal sign are equal to those on the other side of the equal sign.

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