$\frac{5}{7} × \frac{2}{3} =$
$\frac{7}{24} × \frac{3}{14} =$
$1.6 × \frac{17}{32} =$
$0.13 × \frac{7}{13} =$
$\frac{5}{12} × \frac{6}{5} =$
$\frac{9}{4} × \frac{2}{13} =$
$\frac{9}{37} × \frac{26}{3} =$
$\frac{13}{15} × \frac{3}{26} =$
$\frac{4}{13} × \frac{39}{8} =$
$\frac{7}{20} × 40 =$
$\frac{11}{18} × 0.9 =$
$\frac{10}{27} × 0.09 =$
$\frac{7}{30} × \frac{5}{14} =$
$\frac{4}{5} × 5 =$
$\frac{3}{28} × \frac{4}{9} =$
$18 × \frac{5}{24} =$
$\frac{9}{14} × 0.5 =$
$\frac{8}{31} × \frac{62}{7} =$
$\frac{9}{25} × \frac{5}{27} =$
$\frac{7}{3} × \frac{6}{7} =$

1. $\frac{10}{21}$
2. $\frac{1}{16}$
3. $\frac{17}{20}$
4. $0.07$
5. $\frac{1}{2}$
6. $\frac{9}{26}$
7. $\frac{78}{37}$
8. $\frac{1}{10}$
9. $\frac{3}{2}$
10. $14$
11. $\frac{11}{20}$
12. $\frac{1}{30}$
13. $\frac{1}{12}$
14. $4$
15. $\frac{1}{21}$
16. $\frac{15}{4}$
17. $\frac{9}{28}$
18. $\frac{16}{7}$
19. $\frac{1}{15}$
20. $2$

2 脱式计算（能简算的要简算）
建议用时4分钟 评价：☆☆☆
$\frac{11}{20}×\frac{5}{3}-\frac{5}{6}$
$\frac{10}{13}×\frac{3}{8}×\frac{13}{15}$
$\frac{4}{19}×25×19×\frac{3}{5}$
$\frac{5}{9}×\frac{3}{4}+\frac{3}{4}×\frac{4}{9}$
$18×(\frac{1}{3}+\frac{1}{9}-\frac{1}{6})$
$\frac{16}{87}×88$

1. $\frac{1}{12}$
2. $\frac{1}{4}$
3. $60$
4. $\frac{3}{4}$
5. $5$
6. $16\frac{16}{87}$

交换分子法 用简便方法计算下面各题。
$\frac{7}{13}×\frac{23}{45}+\frac{7}{45}×\frac{22}{13}$
$\frac{9}{20}×\frac{6}{17}+\frac{9}{17}×\frac{11}{20}-\frac{3}{20}×3$

1. $\frac{7}{13}$
2. $0$