inverse Calculation

What is the correct inverse of this calculation?

50 + 20 = 70

• 50 - 20 = 70

• 70 - 20 = 40

• 70 - 50 = 20

• 70 - 50 = 50

What is the correct inverse of this calculation?

86 + 13 = 99

• 99 - 13 = 86

• 99 - 86 = 31

• 86 - 13 = 99

• 99 - 13 = 68

What is the correct inverse of this calculation?

45 + 31 = 76

• 45 - 31 = 67

• 76 - 31 = 45

• 76 - 45 = 13

• 45 - 31 = 76

What is the correct inverse of this calculation?

71 - 51 = 20

• 71 - 51 = 2

• 71 - 20 = 15

• 51 + 20 = 17

• 51 + 20 = 71

What is the correct inverse of this calculation?

100 - 60 = 40

• 100 - 60 = 4

• 100 - 40 = 6

• 60 + 40 = 100

• 60 + 40 = 10

Find the missing number :

... + 10 = 80

• 70

• 90

• 7

• 20

Find the missing number :

95 - ... = 90

• 90

• 50

• 5

• 185

Find the missing number :

... + 15 = 45

• 35

• 25

• 30

• 60

Find the missing number :

... - 20 = 30

• 20

• 50

• 15

• 30

Find the missing number :

... + 32 =96

• 32

• 96

• 46

• 64