Grades 3-5 Math Problem Solving in Action_ Getting Students to Love Word Problems

Figure 4.1 Four Strategies for Adding

Partitioning

58 = 50 + 8

+44 = 40 + 4

102 = 90 + 12

Traditional Method

(Grandma’s Way)

1

29

+ 77

106

Using Friendly Numbers (on the number line model)

+40

58 98 102

+4

Compensation

398 + 555

400 + 553 = 953

Figure 4.2 Four Strategies for Subtracting

Partial Differences

102 − 58 = 44

102 − 2 = 100

100 − 56 = 44

Traditional Method

(Grandma’s Way)

102

− 58

44

Counting Up (on the number line model)

+40

58 98 102

+4

Partitioning

102 − 58

90

102 = 100 + 12

–58 = –50 + 8

40 + 4

9 12