5. 计算。
（1）直接写得数。
$0.037×100 =$ $35÷1000 =$ $45.3÷100 =$ $5.42×1000 =$
$250×4 =$ $21×5 =$ $0.7÷100 =$ $0.06×1000 =$
$4.5×10 =$ $40.3÷100 =$ $5.31×100 =$ $4.63÷100 =$
（2）用竖式计算并验算。
$10.48 - 2.35 =$ $100.04 - 9.86 =$ $25.4 + 38.7 =$
$47.65 + 23.31 =$ $23.95 + 9.07 =$ $1.85 - 0.092 =$
（3）怎样简便就怎样算。
$432 + 123 + 77$ $728 - (350 + 228)$ $2×70×25$
$540÷45÷2$ $(25 + 11)×40$ $45×103$

（1）直接写得数
$0.037×100 = 3.7$
$35÷1000 = 0.035$
$45.3÷100 = 0.453$
$5.42×1000 = 5420$
$250×4 = 1000$
$21×5 = 105$
$0.7÷100 = 0.007$
$0.06×1000 = 60$
$4.5×10 = 45$
$40.3÷100 = 0.403$
$5.31×100 = 531$
$4.63÷100 = 0.0463$
（2）用竖式计算并验算
$10.48 - 2.35 = 8.13$
竖式：
```
10.48
2.35
--------
8.13
```
验算：$8.13+2.35 = 10.48$
```
8.13
+ 2.35
--------
10.48
```
$100.04 - 9.86 = 90.18$
竖式：
```
100.04
9.86
--------
90.18
```
验算：$90.18+9.86 = 100.04$
```
90.18
+ 9.86
--------
100.04
```
$25.4 + 38.7 = 64.1$
竖式：
```
25.4
+ 38.7
--------
64.1
```
验算：$64.1 - 38.7 = 25.4$
```
64.1
-38.7
--------
25.4
```
$47.65 + 23.31 = 70.96$
竖式：
```
47.65
+23.31
--------
70.96
```
验算：$70.96 - 23.31 = 47.65$
```
70.96
-23.31
--------
47.65
```
$23.95 + 9.07 = 33.02$
竖式：
```
23.95
+ 9.07
--------
33.02
```
验算：$33.02 - 9.07 = 23.95$
```
33.02
9.07
--------
23.95
```
$1.85 - 0.092 = 1.758$
竖式：
```
1.850
0.092
--------
1.758
```
验算：$1.758+0.092 = 1.85$
```
1.758
+0.092
--------
1.850
```
（3）怎样简便就怎样算
$432 + 123 + 77$
$=432+(123 + 77)=432 + 200 = 632$
$728 - (350 + 228)$
$=728 - 228 - 350 = 500 - 350 = 150$
$2×70×25$
$=2×25×70 = 50×70 = 3500$
$540÷45÷2$
$=540÷(45×2)=540÷90 = 6$
$(25 + 11)×40$
$=25×40+11×40 = 1000 + 440 = 1440$
$45×103$
$=45×(100 + 3)=45×100+45×3 = 4500+135 = 4635$