一、口算。
84 + 34 =
70 × 80 =
7.5 - 5.7 =
96 ÷ 24 =
72 - 27 =
1.3 × 8 =
105 × 7 =
1.03 × 10 =
820 ÷ 4 =
480 ÷ 5 =
14.8 + 2.02 =
1.28 × 2 =
1.04 - 0.4 =
0.21 × 40 =
225 ÷ 15 =
2.6 × 100 =
1600 ÷ 80 =
0.99 + 1.8 =
0.014 × 100 =
0.37 + 0.73 =
65 × 200 =
0.34 × 1000 =
0.022 × 3 =
5.02 × 4 =

1. 84+34=118
2. 70×80=5600
3. 7.5-5.7=1.8
4. 96÷24=4
5. 72-27=45
6. 1.3×8=10.4
7. 105×7=735
8. 1.03×10=10.3
9. 820÷4=205
10. 480÷5=96
11. 14.8+2.02=16.82
12. 1.28×2=2.56
13. 1.04-0.4=0.64
14. 0.21×40=8.4
15. 225÷15=15
16. 2.6×100=260
17. 1600÷80=20
18. 0.99+1.8=2.79
19. 0.014×100=1.4
20. 0.37+0.73=1.1
21. 65×200=13000
22. 0.34×1000=340
23. 0.022×3=0.066
24. 5.02×4=20.08

二、用竖式计算。
$1.69×8=$
$0.12×36=$
$1.08×45=$
$2.9×17=$
$1.36×80=$
$0.321×15=$

1. 1.69×8=13.52
2. 0.12×36=4.32
3. 1.08×45=48.6
4. 2.9×17=49.3
5. 1.36×80=108.8
6. 0.321×15=4.815