一、口算。
$84 - 26 =$
$56 × 2 =$
$400 × 6 =$
$58 × 5 =$
$16 + 89 =$
$154 - 39 =$
$60 ÷ 4 =$
$5 × 28 =$
$305 × 3 =$
$148 + 30 =$
$91 ÷ 7 =$
$167 + 233 =$
$72 ÷ 3 =$
$560 - 423 =$
$140 ÷ 2 =$
$18 × 5 =$
$57 ÷ 3 =$
$210 × 8 =$
$68 ÷ 4 =$
$802 ÷ 2 =$
$720 - 200 =$
$2 × 98 =$
$480 + 52 =$
$450 ÷ 3 =$

1. 58
2. 112
3. 2400
4. 290
5. 105
6. 115
7. 15
8. 140
9. 915
10. 178
11. 13
12. 400
13. 24
14. 137
15. 70
16. 90
17. 19
18. 1680
19. 17
20. 401
21. 520
22. 196
23. 532
24. 150

二、计算下面各题。
$280÷(6+1)$
$265+992÷8$
$640÷8×9$
$7×(354-316)$
$(205+125)÷5$
$1000-168×4$

1. 40
2. 389
3. 720
4. 266
5. 66
6. 328