1. 计算。
(1)口算。
1.9-0.9=
56÷0.8=
2-1.5=
0.2×0.4=
9.5-7.7=
1.5×3=
20÷8=
0.5÷0.5=
0.1×50=
0.45+0.55=
90÷100=
7.1-3.5=
5×0.3=
0.5×40=
0.36÷9=
0.18÷0.6=
0.82+0.8=
1÷0.01=
8÷0.08=
0÷9.6=

1. 计算。
(1)口算。
1.9 - 0.9 = 1
56 ÷ 0.8 = 70
2 - 1.5 = 0.5
0.2 × 0.4 = 0.08
9.5 - 7.7 = 1.8
1.5 × 3 = 4.5
20 ÷ 8 = 2.5
0.5 ÷ 0.5 = 1
0.1 × 50 = 5
0.45 + 0.55 = 1
90 ÷ 100 = 0.9
7.1 - 3.5 = 3.6
5 × 0.3 = 1.5
0.5 × 40 = 20
0.36 ÷ 9 = 0.04
0.18 ÷ 0.6 = 0.3
0.82 + 0.8 = 1.62
1 ÷ 0.01 = 100
8 ÷ 0.08 = 100
0 ÷ 9.6 = 0

(2)用竖式计算。(带“※”的精确到百分位。)
11.05-9.2=
```
11.05
9.20
------
1.85
```
73.56+0.48=
```
73.56
+ 0.48
------
74.04
```
15×1.28=
```
1.28
× 15
------
6.40
12.8
------
19.20
```
0.35×1.76=
```
0.35
×1.76
------
210
245
35
------
0.6160
```
38.5÷11=
```
3.5
11)38.5
33
---
55
55
---
0
```
※4.56÷1.3≈
```
3.507
13)45.600
39
---
66
65
---
100
91
---
90
78
---
120
117
---
3
```
（精确到百分位，四舍五入得3.51）
6.75+3.25×50=
18.6÷[0.4×(3.4-1.9)]=

11.05-9.2=1.85
```
11.05
9.20
------
1.85
```
73.56+0.48=74.04
```
73.56
+ 0.48
------
74.04
```
15×1.28=19.2
```
1.28
× 15
------
6.40
12.8
------
19.20
```
0.35×1.76=0.616
```
0.35
×1.76
------
210
245
35
------
0.6160
```
38.5÷11=3.5
```
3.5
11)38.5
33
---
55
55
---
0
```
※4.56÷1.3≈3.51
```
3.507
13)45.600
39
---
66
65
---
100
91
---
90
78
---
120
117
---
3
```
（精确到百分位，四舍五入得3.51）
6.75+3.25×50=6.75+162.5=169.25
18.6÷[0.4×(3.4-1.9)]=18.6÷[0.4×1.5]=18.6÷0.6=31