一、口算。
$10.2×0.2=$
$12.5×200=$
$24.5×0.2=$
$0.4-0.04=$
$2.7+8.3=$
$15×0.8=$
$3-0.13=$
$50×2.4=$
$24.5-4.05=$
$2.4×0.3=$
$4.32÷0.08=$
$320÷0.16=$
$\frac{7}{27}÷\frac{5}{9}=$
$0.8÷\frac{3}{50}=$
$\frac{3}{7}×21=$
$2×\frac{2}{3}=$
$\frac{7}{8}+\frac{1}{6}=$
$9÷\frac{6}{7}=$
$\frac{4}{15}÷\frac{8}{5}=$
$\frac{5}{7}×\frac{21}{25}=$
$\frac{8}{9}-\frac{2}{3}=$
$\frac{8}{3}×0.3=$
$\frac{1}{6}+\frac{1}{9}=$
$\frac{2}{13}÷\frac{8}{13}=$

1. 2.04
2. 2500
3. 4.9
4. 0.36
5. 11
6. 12
7. 2.87
8. 120
9. 20.45
10. 0.72
11. 54
12. 2000
13. $\frac{7}{15}$
14. $\frac{40}{3}$
15. 9
16. $\frac{4}{3}$
17. $\frac{25}{24}$
18. $\frac{21}{2}$
19. $\frac{1}{6}$
20. $\frac{3}{5}$
21. $\frac{2}{9}$
22. $\frac{4}{5}$
23. $\frac{5}{18}$
24. $\frac{1}{4}$

二、计算下面各题，能简算的要简算。
$\frac{2}{7}×\frac{3}{4}÷\frac{2}{7}×\frac{3}{4}$
$(\frac{3}{7}+\frac{3}{5})×7+\frac{4}{5}$
$56×(\frac{4}{7}+\frac{5}{8}-\frac{3}{4})$
$7.85-(2.85+0.37)$
$2.5×8.1×0.4÷0.3$
$(71.2-71.2×0.9)÷0.25$

1. $\frac{9}{16}$
2. 8
3. 25
4. 4.63
5. 27
6. 28.48