一、口算。
5.5 + 7.2 =
8 × 3.5 =
1.38 × 2 =
11.8 - 8.9 =
10.8 ÷ 20 =
4.8 + 8.4 =
6.9 - 0.01 =
3.28 + 7.2 =
6.5 × 0.6 =
6.6 ÷ 0.33 =
9.12 + 0.8 =
7.2 - 0.12 =
0.35 ÷ 0.7 =
2.7 × 0.5 =
1.85 - 0.95 =
$\frac{10}{9} - \frac{5}{6} =$
$\frac{5}{8} - \frac{1}{4} =$
$\frac{5}{24} + \frac{3}{8} =$
$\frac{1}{4} + \frac{13}{28} =$
$\frac{1}{10} + \frac{7}{10} =$
$\frac{1}{5} - \frac{1}{6} =$
$\frac{5}{6} - \frac{3}{4} =$
$3 - \frac{2}{3} =$
$\frac{5}{16} + \frac{5}{12} =$

1. 12.7
2. 28
3. 2.76
4. 2.9
5. 0.54
6. 13.2
7. 6.89
8. 10.48
9. 3.9
10. 20
11. 9.92
12. 7.08
13. 0.5
14. 1.35
15. 0.9
16. $\frac{5}{18}$
17. $\frac{3}{8}$
18. $\frac{7}{12}$
19. $\frac{5}{7}$
20. $\frac{4}{5}$
21. $\frac{1}{30}$
22. $\frac{1}{12}$
23. $2\frac{1}{3}$
24. $\frac{35}{48}$

二、计算下面各题，能用简便算法的就用简便算法。
$\frac{7}{13} + \frac{11}{39} - \frac{2}{13}$
$\frac{5}{9} + \frac{2}{3} - \frac{2}{5}$
$\frac{1}{5} + \frac{1}{13} + (\frac{4}{5} + \frac{4}{13})$
$\frac{7}{8} + \frac{1}{6} - \frac{3}{4}$
$\frac{15}{8} - (\frac{7}{8} + \frac{8}{15})$
$\frac{7}{2} + \frac{3}{2} - \frac{1}{2} - \frac{3}{2}$

1. $\frac{2}{3}$
2. $\frac{37}{45}$
3. $1\frac{5}{13}$
4. $\frac{7}{24}$
5. $\frac{7}{15}$
6. 3