一、口算。
$47 + 28 =$
$9 × 7 =$
$37 + 46 =$
$48 ÷ 4 =$
$320 + 80 =$
$43 × 2 =$
$54 ÷ 9 =$
$400 + 900 =$
$42 ÷ 2 =$
$530 - 220 =$
$11 × 8 =$
$39 ÷ 6 =$
$31 × 2 =$
$62 + 38 =$
$25 ÷ 9 =$
$12 × 3 =$
$310 - 60 =$
$250 + 80 =$
$60 + 260 =$
$32 ÷ 4 =$
$83 - 67 =$
$4 × 7 =$
$180 - 90 =$
$41 × 2 =$

75
63
 83
12
400
86
6
 1300
 21
310
 88
 6······3
62
 100
 2······7
36
 250
 330
320
 8
 16
28
90
82

二、用竖式计算。
$630 - 437 - 107$
$127 + 573 - 349$
$358 - 239 + 457$
$248 + 619 - 532$
$656 - 284 - 317$
$265 + 379 + 136$

解：
1. $630 - 437 - 107$
630
- 437
-----
193

193
- 107
-----
86

$630 - 437 - 107 = 86$
2. $127 + 573 - 349$

127
+ 573
-----
700


700
- 349
-----
351

$127 + 573 - 349 = 351$
3. $358 - 239 + 457$

358
- 239
-----
119


119
+ 457
-----
576

$358 - 239 + 457 = 576$
4. $248 + 619 - 532$

248
+ 619
-----
867


867
- 532
-----
335
```
$248 + 619 - 532 = 335$
5. $656 - 284 - 317$
```
656
- 284
-----
372


372
- 317
-----
55

$656 - 284 - 317 = 55$
6. $265 + 379 + 136$

265
+ 379
-----
644


644
+ 136
-----
780

$265 + 379 + 136 = 780$