Addition and Subtraction Within 20

Front

What is the sum of 7 and 5?

Back

12

Front

What is the sum of 8 and 9?

Back

17

Front

What is the sum of 8 and 4?

Back

12

Front

What is 15 minus 7?

Back

8

Front

What is 16 minus 6?

Back

10

Front

What is the definition of addition?

Back

Addition is the mathematical operation of combining two or more numbers to get a total.

Front

What is the definition of subtraction?

Back

Subtraction is the mathematical operation of taking one number away from another.

Front

What is the commutative property of addition?

Back

The commutative property of addition states that changing the order of the addends does not change the sum.

Front

What is the associative property of addition?

Back

The associative property of addition states that the way in which numbers are grouped does not change their sum.

Front

What is a number line and how is it used in addition and subtraction?

Back

A number line is a visual representation of numbers on a straight line, used to illustrate addition and subtraction by moving right for addition and left for subtraction.