一、口算。
900 + 50 =
71 - 24 =
150 × 6 =
80 + 460 =
177 - 60 =
3 × 301 =
88 - 14 =
180 × 2 =
270 - 90 =
300 × 7 =
44 × 3 =
350 + 70 =
55 × 3 =
28 + 16 =
700 - 430 =
25 × 5 =
600 × 5 =
103 × 5 =
101 × 4 =
240 + 120 =
135 × 2 =
230 × 3 =
382 + 225 =
825 - 630 =

1. 900 + 50 = 950
2. 71 - 24 = 47
3. 150 × 6 = 900
4. 80 + 460 = 540
5. 177 - 60 = 117
6. 3 × 301 = 903
7. 88 - 14 = 74
8. 180 × 2 = 360
9. 270 - 90 = 180
10. 300 × 7 = 2100
11. 44 × 3 = 132
12. 350 + 70 = 420
13. 55 × 3 = 165
14. 28 + 16 = 44
15. 700 - 430 = 270
16. 25 × 5 = 125
17. 600 × 5 = 3000
18. 103 × 5 = 515
19. 101 × 4 = 404
20. 240 + 120 = 360
21. 135 × 2 = 270
22. 230 × 3 = 690
23. 382 + 225 = 607
24. 825 - 630 = 195

二、计算下面各题。
$(9+24)÷3$
$(173-135)×4$
$31×2+546$
$(166+4)×2$
$105×4×3$
$500-(204+132)$

1. $(9+24)÷3 = 11$
2. $(173-135)×4 = 152$
3. $31×2+546 = 608$
4. $(166+4)×2 = 340$
5. $105×4×3 = 1260$
6. $500-(204+132) = 164$