Solve for the unknown number

Front

2 + __ = 7

Back

5

Front

__ - 12 = 4

Back

16

Front

18 - __ = 10

Back

8

Front

__ - 3 = 9

Back

12

Front

4 + __ = 11

Back

7

Front

What is an unknown number?

Back

An unknown number is a number we don't know yet, often represented by a blank or a symbol like __.

Front

How do you find an unknown number in addition?

Back

To find an unknown number in addition, subtract the known number from the total.

Front

How do you find an unknown number in subtraction?

Back

To find an unknown number in subtraction, add the number being subtracted to the result.

Front

What does the equal sign (=) mean?

Back

The equal sign means that both sides of the equation are the same.

Front

What is the total in the equation 2 + __ = 7?

Back

The total is 7.