We use number sentences to represent problems in mathematics. Watch this video to see how.

When you see the equal sign it means both sides have to balance. A number sentence is like a set of scales. To keep it balanced, both sides need to equal the same number. Look at the picture below. We can see there are 5 blocks on one side and 5 blocks on the other, so it is balanced.

When the two sides of the number sentence are equal we say the statement is true.

Example: Fill in the missing number to make the number sentence true.