Number (add/sub)

Lesson

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.

$4+2=3+\editable{}$4+2=3+

The missing number must be $3$3.

True or false?

$6+2=8$6+2=8

True

AFalse

BTrue

AFalse

B

Complete the number sentence:

$10+\editable{}=18$10+=18

Complete the number sentence:

$5+7=8+\editable{}$5+7=8+