一、口算。
13 - 6 = 2 + 9 = 85 - 40 - 5 =
68 + 7 = 89 - 50 = 65 + 9 - 60 =
62 - 7 = 40 + 37 = 98 - 80 + 5 =
6 + 68 = 17 - 8 = 18 + 9 + 8 =
97 - 30 = 51 + 9 = 80 - 50 + 26 =
72 + 10 = 90 - 6 = 58 + 5 - 20 =
80 - 50 = 60 + 20 = 18 + 40 + 6 =
34 + 9 = 61 - 8 = 72 - 8 + 20 =
43 - 8 = 28 + 8 = 56 + 4 + 17 =
57 + 6 = 75 - 60 = 96 - 70 + 4 =

一、7 11 40
75 39 14
55 77 23
74 9 35
67 60 56
82 84 43
30 80 64
43 53 84
35 36 77
63 15 30

二、在得数是六十多的算式后面画“√”。
45 + 20 □ 45 + 2 □ 72 - 30 □
72 - 3 □ 96 - 30 □ 78 - 9 □
85 - 30 □ 58 + 9 □ 76 - 5 □

二、