一、口算。
$70÷ 3.5=$
$1.9-0.39=$
$1.4× 0.06=$
$0.605-0.505=$
$4.78÷ 0.01=$
$3.2+5.8=$
$4.25× 3=$
$6.12+0.56=$
$11÷ 0.22=$
$7.2× 0.5=$
$0.84÷ 12=$
$2.07+1.83=$
$1-\dfrac{3}{10}=$
$12× \dfrac{3}{8}=$
$\dfrac{4}{5}÷ \dfrac{3}{5}=$
$\dfrac{2}{3}-\dfrac{1}{5}=$
$\dfrac{2}{3}÷ \dfrac{3}{5}=$
$\dfrac{7}{20}÷ \dfrac{4}{15}=$
$\dfrac{2}{5}÷ 10=$
$2-\dfrac{2}{5}=$
$1.6× \dfrac{3}{8}=$
$\dfrac{7}{18}÷ \dfrac{5}{9}=$
$\dfrac{8}{9}× \dfrac{3}{2}=$
$\dfrac{8}{27}÷ \dfrac{2}{9}=$

1. 20
2. 1.51
3. 0.084
4. 0.1
5. 478
6. 9
7. 12.75
8. 6.68
9. 50
10. 3.6
11. 0.07
12. 3.9
13. $\dfrac{7}{10}$
14. $\dfrac{9}{2}$
15. $\dfrac{4}{3}$
16. $\dfrac{7}{15}$
17. $\dfrac{10}{9}$
18. $\dfrac{21}{16}$
19. $\dfrac{1}{25}$
20. $1\dfrac{3}{5}$
21. $\dfrac{3}{5}$
22. $\dfrac{7}{10}$
23. $\dfrac{4}{3}$
24. $\dfrac{4}{3}$

二、计算下面各题，能简算的要简算。
$\frac{8}{7} - ( \frac{1}{9} - \frac{1}{12} ) × 3.6$
$\frac{7}{13} × \frac{4}{5} + \frac{6}{13} ÷ \frac{5}{4}$
$( 2.5 + \frac{5}{8} + \frac{5}{12} ) ÷ 5$
$7.08 × 101 - 7.08$
$79.8 ÷ 4.2 + 79.8 ÷ 3.8$
$52 ÷ [ 1.6 × (4.1 - 0.85) ]$

1. $\dfrac{73}{70}$
2. $\dfrac{4}{5}$
3. $\dfrac{17}{24}$
4. 708
5. 40
6. 10