一、口算。
83 - 4 =
6 + 8 =
63 - 5 + 20 =
76 + 8 =
14 - 7 =
90 - 20 - 3 =
72 - 30 =
53 + 40 =
6 + 49 - 50 =
10 + 57 =
42 - 9 =
31 + 8 + 4 =
64 - 30 =
86 + 5 =
51 - 9 + 30 =
7 + 83 =
79 - 50 =
50 + 5 - 6 =
91 - 3 =
50 + 28 =
89 - 50 - 7 =
23 + 60 =
85 - 8 =
37 - 8 + 20 =
86 - 40 =
19 + 7 =
44 + 20 + 6 =
4 + 76 =
98 - 80 =
60 - 4 - 8 =

一、79 14 78 84 7 67 42 93 5 67 33 43 34 91 72 90 29 49 88 78 32 83 77 49 46 26 70 80 18 48

二、给下面的算式排排队。(填序号)

()＜()＜()＜()＜()

二、② ⑤ ① ④ ③