三、算一算。
1.直接写出得数。
$240÷3=$
$0÷5=$
$69÷3=$
$630÷9=$
$6000÷2=$
$270÷9=$
$200÷5=$
$203÷4\approx$
$364÷6\approx$

240÷3=80
0÷5=0
69÷3=23
630÷9=70
6000÷2=3000
270÷9=30
200÷5=40
203÷4≈50
364÷6≈60

2. 列竖式计算。(带*的要验算)
89 ÷ 6 =
725 ÷ 5 =
408. ÷ 3 =
780 ÷ 4 =
568 ÷ 7 =
504. ÷ 8 =

89 ÷ 6 = 14……5
```
14
6)89
6
---
29
24
---
5
```
725 ÷ 5 = 145
```
145
5)725
5
---
22
20
---
25
25
---
0
```
*408 ÷ 3 = 136
```
136
3)408
3
---
10
9
---
18
18
---
0
```
验算：
```
136
× 3
----
408
```
780 ÷ 4 = 195
```
195
4)780
4
---
38
36
---
20
20
---
0
```
568 ÷ 7 = 81……1
```
81
7)568
56
---
8
7
---
1
```
*504 ÷ 8 = 63
```
63
8)504
48
---
24
24
---
0
```
验算：
```
63
× 8
----
504
```

3.脱式计算。
$285 + 399 ÷ 7$
$912 ÷ (2 × 4)$
$624 ÷ (13 - 7)$

$285 + 399 ÷ 7$
$= 285 + 57$
$= 342$
$912 ÷ (2 × 4)$
$= 912 ÷ 8$
$= 114$
$624 ÷ (13 - 7)$
$= 624 ÷ 6$
$= 104$