一、口算。
$67 + 2 =$
$15 - 8 =$
$66 - 20 + 10 =$
$53 - 5 =$
$48 + 5 =$
$49 + 4 + 5 =$
$35 + 45 =$
$44 - 40 =$
$14 - 9 + 20 =$
$71 - 2 =$
$28 + 32 =$
$36 + 8 - 22 =$
$87 + 5 =$
$77 - 52 =$
$82 - 71 + 7 =$
$40 - 4 =$
$16 + 45 =$
$93 - 22 + 9 =$
$55 + 33 =$
$80 - 7 =$
$62 + 15 - 20 =$
$53 - 22 =$
$36 + 35 =$
$71 - 6 + 30 =$
$67 + 15 =$
$99 - 44 =$
$65 - 31 + 20 =$
$67 - 24 =$
$32 + 49 =$
$78 - 22 + 7 =$

1.69
2.7
3.56
4.48
5.53
6.58
7.80
8.4
9.25
10.69
11.60
12.22
13.92
14.25
15.18
16.36
17.61
18.80
19.88
20.73
21.57
22.31
23.71
24.95
25.82
26.55
27.54
28.43
29.81
30.63

二、填一填。

82 55 90 63 73
40 52 63 74 86