Subtracting

There were 10 chairs in a room . 7 guests occupied the chairs . How many chairs were left blank?

• 3

• 4

• 6

• 2

• 17

• 5

• 11

30 - 20 =

• 50

• 20

• 10

• 15

50 - 40 =

• 10

• 90

• 40

• 50

60 - 10 =

• 50

• 70

• 40

• 50

70 - 40 =

• 40

• 50

• 110

• 30

70 - 20 =

• 10

• 90

• 50

• 20

90 - 60 =

• 30

• 120

• 50

• 10

80 - 70 =

• 150

• 90

• 10

• 80

90 - 10 =

• 100

• 110

• 80

• 99