一、直接写出得数。（共28分）
3.14÷0.2=
0.15×8=
7.2+0.64=
6.6÷2.2×0.1=
75×0.01=
1.8-0.08=
8.4÷4.2=
0.6×0.6÷0.4=
4.6-2.31=
0.8×0.7=
3.07-1.2=
13-5.6+4.3=
4.07+1.25=
2.6×0.5=
0.75÷2.5=
5-0.4×0.9=
3.6÷4=
4.5+4.5=
0.49÷0.07=
$3.14×(0.4÷2)^2=$
1-0.52=
2.7×0.3=
1.3×70=
0.38+9.5+1.62=
4.6×5=
13.2+1.72=
6.78÷2=
30÷1.25÷4=

1. 3.14÷0.2=15.7
2. 0.15×8=1.2
3. 7.2+0.64=7.84
4. 6.6÷2.2×0.1=0.3
5. 75×0.01=0.75
6. 1.8-0.08=1.72
7. 8.4÷4.2=2
8. 0.6×0.6÷0.4=0.9
9. 4.6-2.31=2.29
10. 0.8×0.7=0.56
11. 3.07-1.2=1.87
12. 13-5.6+4.3=11.7
13. 4.07+1.25=5.32
14. 2.6×0.5=1.3
15. 0.75÷2.5=0.3
16. 5-0.4×0.9=4.64
17. 3.6÷4=0.9
18. 4.5+4.5=9
19. 0.49÷0.07=7
20. $3.14×(0.4÷2)^2=$0.1256
21. 1-0.52=0.48
22. 2.7×0.3=0.81
23. 1.3×70=91
24. 0.38+9.5+1.62=11.5
25. 4.6×5=23
26. 13.2+1.72=14.92
27. 6.78÷2=3.39
28. 30÷1.25÷4=6

二、计算下面各题，怎样算简便就怎样算。（共24分）
$(12.5 + 1.25) × 0.8$
$2.4 × ( \frac{3}{8} + \frac{1}{6} + \frac{5}{12} )$
$\frac{4}{9} × 15 + \frac{5}{9} ÷ \frac{1}{15}$
$( 3 - \frac{1}{2} ) ÷ (0.25 + 2)$
$2.4 × ( \frac{1}{12} + \frac{1}{13} ) × 3.9$
$1.2 × 6 ÷ (2.5 - 0.25)$
$12.84 ÷ [ 4 × (1.39 - 0.19) ]$
$9\frac{9}{20} ÷ [ (38.02 + 1.98) × 0.5 ]$

1. $(12.5 + 1.25) × 0.8 = 11$
2. $2.4 × ( \frac{3}{8} + \frac{1}{6} + \frac{5}{12} ) = 2.3$
3. $\frac{4}{9} × 15 + \frac{5}{9} ÷ \frac{1}{15} = 15$
4. $( 3 - \frac{1}{2} ) ÷ (0.25 + 2) = \frac{10}{9}$
5. $2.4 × ( \frac{1}{12} + \frac{1}{13} ) × 3.9 = 1.5$
6. $1.2 × 6 ÷ (2.5 - 0.25) = 3.2$
7. $12.84 ÷ [ 4 × (1.39 - 0.19) ] = 2.675$
8. $9\frac{9}{20} ÷ [ (38.02 + 1.98) × 0.5 ] = \frac{189}{400}$

三、化简下面各比。（共12分）
$5.6:14$
$2.15:0.645$
$\frac{3}{10}:1.4$
$\frac{7}{8}\mathrm{m}^3:150\mathrm{dm}^3$

1. $5.6:14 = 2:5$
2. $2.15:0.645 = 10:3$
3. $\frac{3}{10}:1.4 = 3:14$
4. $\frac{7}{8}\mathrm{m}^3:150\mathrm{dm}^3 = 35:6$