Add and subtract within 20

Front

What is the sum of 4 and 9?

Back

13

Front

What is 20 minus 13?

Back

7

Front

What is the sum of 1 and 7?

Back

8

Front

What is the sum of 4 and 4?

Back

8

Front

What is the sum of 12 and 7?

Back

19

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 states that changing the order of the numbers in an addition problem does not change the sum.

Front

What is the associative property of addition?

Back

The associative property states that the way in which numbers are grouped in an addition problem does not change the 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 in a straight line, used to illustrate addition and subtraction by moving right for addition and left for subtraction.