一、口算。
0.78 + 2.02 =
0.27 ÷ 0.9 =
0.36 ÷ 18 =
0.408 ÷ 0.8 =
3.36 ÷ 0.6 =
5.2 + 3.28 =
2.8 ÷ 0.5 =
0.68 × 3 =
9.6 ÷ 16 =
0.65 × 0.2 =
43.2 ÷ 0.6 =
1.8 × 0.5 =
$\frac{7}{20} ÷ 14 =$
$\frac{9}{10} - \frac{5}{8} =$
$1 ÷ ( \frac{1}{3} + \frac{1}{4} ) =$
$\frac{5}{6} × \frac{2}{3} =$
$\frac{3}{4} ÷ \frac{1}{4} =$
$1 ÷ ( \frac{1}{8} + \frac{1}{10} ) =$
$0.4 + \frac{4}{25} =$
$\frac{1}{12} × \frac{4}{7} =$
$\frac{1}{2} ÷ ( \frac{1}{9} + \frac{1}{12} ) =$
$\frac{4}{25} ÷ \frac{12}{5} =$
$\frac{5}{24} × 0.3 =$
$( \frac{1}{18} + \frac{1}{20} ) × 5 =$

1. 0.78 + 2.02 = 2.8
2. 0.27 ÷ 0.9 = 0.3
3. 0.36 ÷ 18 = 0.02
4. 0.408 ÷ 0.8 = 0.51
5. 3.36 ÷ 0.6 = 5.6
6. 5.2 + 3.28 = 8.48
7. 2.8 ÷ 0.5 = 5.6
8. 0.68 × 3 = 2.04
9. 9.6 ÷ 16 = 0.6
10. 0.65 × 0.2 = 0.13
11. 43.2 ÷ 0.6 = 72
12. 1.8 × 0.5 = 0.9
13. $\frac{7}{20} ÷ 14 = \frac{1}{40}$
14. $\frac{9}{10} - \frac{5}{8} = \frac{11}{40}$
15. $1 ÷ ( \frac{1}{3} + \frac{1}{4} ) = \frac{12}{7}$
16. $\frac{5}{6} × \frac{2}{3} = \frac{5}{9}$
17. $\frac{3}{4} ÷ \frac{1}{4} = 3$
18. $1 ÷ ( \frac{1}{8} + \frac{1}{10} ) = \frac{40}{9}$
19. $0.4 + \frac{4}{25} = \frac{14}{25}$
20. $\frac{1}{12} × \frac{4}{7} = \frac{1}{21}$
21. $\frac{1}{2} ÷ ( \frac{1}{9} + \frac{1}{12} ) = \frac{18}{7}$
22. $\frac{4}{25} ÷ \frac{12}{5} = \frac{1}{15}$
23. $\frac{5}{24} × 0.3 = \frac{1}{16}$
24. $( \frac{1}{18} + \frac{1}{20} ) × 5 = \frac{19}{36}$

二、计算下面各题，能简算的要简算。
$\frac{5}{7}×16 - 2÷\frac{7}{5}$
$(\frac{1}{15} + \frac{3}{49})×15 - \frac{45}{49}$
$(\frac{1}{5} + \frac{2}{3} - \frac{4}{15})÷\frac{1}{30}$
$12.5×32×12.5$
$7.8×2.4 + 2.2×2.4$
$[1 - (0.4 + 0.45)]÷0.15$

1. $\frac{5}{7}×16 - 2÷\frac{7}{5} = 10$
2. $(\frac{1}{15} + \frac{3}{49})×15 - \frac{45}{49} = 1$
3. $(\frac{1}{5} + \frac{2}{3} - \frac{4}{15})÷\frac{1}{30} = 18$
4. $12.5×32×12.5 = 5000$
5. $7.8×2.4 + 2.2×2.4 = 24$
6. $[1 - (0.4 + 0.45)]÷0.15 = 1$