6.（1）积接近几十或几百。
$19×4\approx$
$33×3\approx$
$396×2\approx$
$503×5\approx$
（2）商接近几十或几百。
$96÷5\approx$
$108÷2\approx$
$589÷3\approx$
$495÷7\approx$

19×4≈80
33×3≈90
396×2≈800
503×5≈2500
96÷5≈20
108÷2≈50
589÷3≈200
495÷7≈70

7.用竖式计算。(带“*”的要验算。)
$703× 6$
$522÷ 9$
$490× 3$
$672÷ 6$
$45× 8$
$202÷ 5$
$*756÷ 7$
$*618÷ 3$

```
703
× 6
------
4218
```
$703×6=4218$
---
```
58
9)522
45
------
72
72
------
0
```
$522÷9=58$
---
```
490
× 3
------
1470
```
$490×3=1470$
---
```
112
6)672
6
------
7
6
------
12
12
------
0
```
$672÷6=112$
---
```
45
× 8
----
360
```
$45×8=360$
---
```
40
5)202
20
------
2
```
$202÷5=40······2$
---
```
108
7)756
7
------
5
0
------
56
56
------
0
```
验算：
```
108
× 7
------
756
```
$756÷7=108$
---
```
206
3)618
6
------
1
0
------
18
18
------
0
```
验算：
```
206
× 3
------
618
```
$618÷3=206$