1.算一算,填一填。

$\frac{16}{15}×\frac{2}{3}=\frac{32}{45}$
$\frac{3}{20}×\frac{2}{3}=\frac{1}{10}$
$4×\frac{2}{3}=\frac{8}{3}$
$30×\frac{2}{3}=20$
$\frac{3}{2}×\frac{7}{10}=\frac{21}{20}$
$\frac{4}{5}×\frac{7}{10}=\frac{14}{25}$
$\frac{8}{9}×\frac{7}{10}=\frac{28}{45}$
$\frac{33}{2}×\frac{7}{10}=\frac{231}{20}$
（从左到右，从上到下依次填入：$\frac{32}{45}$，$\frac{1}{10}$，$\frac{8}{3}$，$20$；$\frac{21}{20}$，$\frac{14}{25}$，$\frac{28}{45}$，$\frac{231}{20}$）

2.脱式计算。
$\frac{9}{25}×\frac{5}{3}$ $\frac{2}{3}×\frac{9}{10}$ $\frac{3}{4}×\frac{1}{3}$
$\frac{7}{9}×\frac{3}{7}$ $\frac{5}{7}×\frac{5}{8}$ $15×\frac{2}{3}$
$\frac{5}{8}×\frac{1}{5}$ $\frac{1}{12}×\frac{4}{9}$ $\frac{1}{4}×\frac{3}{16}$
$\frac{4}{5}×\frac{5}{8}$ $\frac{4}{25}×25$ $\frac{16}{23}×\frac{23}{8}$
$\frac{1}{15}×\frac{3}{8}$ $\frac{7}{12}×\frac{3}{7}$ $\frac{4}{15}×\frac{25}{8}$

$\frac{9}{25}×\frac{5}{3}=\frac{3}{5}$
$\frac{2}{3}×\frac{9}{10}=\frac{3}{5}$
$\frac{3}{4}×\frac{1}{3}=\frac{1}{4}$
$\frac{7}{9}×\frac{3}{7}=\frac{1}{3}$
$\frac{5}{7}×\frac{5}{8}=\frac{25}{56}$
$15×\frac{2}{3}=10$
$\frac{5}{8}×\frac{1}{5}=\frac{1}{8}$
$\frac{1}{12}×\frac{4}{9}=\frac{1}{27}$
$\frac{1}{4}×\frac{3}{16}=\frac{3}{64}$
$\frac{4}{5}×\frac{5}{8}=\frac{1}{2}$
$\frac{4}{25}×25=4$
$\frac{16}{23}×\frac{23}{8}=2$
$\frac{1}{15}×\frac{3}{8}=\frac{1}{40}$
$\frac{7}{12}×\frac{3}{7}=\frac{1}{4}$
$\frac{4}{15}×\frac{25}{8}=\frac{5}{6}$