Finding the Unknown Number in an Equation

8 + ? = 16

• 7

• 10

• 9

• 8

3 + ? = 12

• 15

• 9

• 10

• 6

15+__=21

• 7

• 6

• 8

Find the missing addend for this equation 
5+__= 8

• 3

• 6

• 5

• 8

10+_=15

• 9

• 1

• 5

• 8

Find the missing addend for this equation
__+ 6 = 10

• 9

• 4

• 2

• 6

Find the missing addend for this equation
4+__= 7

• 7

• 8

• 3

• 4

• 4

• 7

• 5

• 6

• 6

• 8

• 9

• 7

• 10

• 8

• 5

• 9