Count On and Count Back

Fill in the missing number.

77, 78, 79, ( )

Fill in the missing number.

54, 53, 52, 51, 50, ( )

Use the count back strategy to find the difference of 87 and 56.

• 33

• 143

• 31

• 80 + 7

Count back to subtract. Use a number line to help you.

6 – 4=........

• 5

• 3

• 2

• 4

Count back to subtract. Use a number line to help you.

15 – 7 = .........

• 8

• 9

• 7

• 10

Jack has 7 trading cards.

He gives 4 cards to Bart.

How many trading cards does Jack have now?

• 5

• 4

• 3

• 2

Which explains how to use a number line to find 9 – 5?

• Start at 9 and count back 5 moves until you reach 4

• Start at 9 and count up 5 moves until you reach 14

• Start at 5 and count back 4 moves until you reach 1

• Start at 5 and count up 9 moves until you reach 14

Count back 250 from 300

Count back 200 from 1000

Count back 125 from 400