一、口算。
$\frac {3}{4}-\frac {5}{18}=$
$\frac {5}{9}÷\frac {5}{6}=$
$\frac {7}{12}+\frac {5}{9}=$
$\frac {4}{9}÷\frac {1}{3}=$
$\frac {3}{8}×2=$
$\frac {5}{8}÷\frac {3}{4}=$
$\frac {7}{27}×\frac {9}{14}=$
$7÷\frac {3}{5}=$
$3-\frac {11}{9}=$
$34÷\frac {17}{2}=$
$\frac {3}{4}÷\frac {3}{8}=$
$\frac {5}{6}+\frac {1}{2}=$
$\frac {5}{7}×\frac {14}{45}=$
$\frac {5}{14}-\frac {2}{7}=$
$10×\frac {2}{5}=$
$\frac {1}{20}+\frac {2}{5}=$
$\frac {2}{9}÷\frac {4}{9}=$
$\frac {2}{3}÷5=$
$\frac {2}{3}×\frac {4}{5}=$
$\frac {3}{5}-\frac {3}{8}=$
$\frac {9}{10}×\frac {5}{21}=$

一、$\frac{17}{36}$ $\frac{2}{3}$ $\frac{41}{36}$ $\frac{4}{3}$ $\frac{3}{4}$ $\frac{5}{6}$ $\frac{1}{6}$ $\frac{35}{3}$ $\frac{16}{9}$ $4$ $2$ $\frac{4}{3}$ $\frac{2}{9}$ $\frac{1}{14}$ $4$ $\frac{9}{20}$ $\frac{1}{2}$ $\frac{2}{15}$ $\frac{8}{15}$ $\frac{9}{40}$ $\frac{3}{14}$

二、计算下面各题。
$\frac {3}{5}×\frac {5}{27}×\frac {3}{8}$
$\frac {7}{10}÷8÷\frac {14}{5}$
$\frac {1}{4}×\frac {8}{9}÷\frac {9}{10}$
$\frac {3}{10}÷18×\frac {4}{7}$
$\frac {7}{5}×6÷\frac {14}{15}$
$\frac {9}{22}÷\frac {3}{4}÷\frac {8}{33}$

二、$\frac{1}{24}$ $\frac{1}{32}$ $\frac{20}{81}$ $\frac{1}{105}$ $9$ $\frac{9}{4}$

$\frac{3}{5}×\frac{5}{27}×\frac{3}{8}$
$=\frac{3×5×3}{5×27×8}$
$=\frac{1}{24}$
$\frac{7}{10}÷8÷\frac{14}{5}$
$=\frac{7}{10}×\frac{1}{8}×\frac{5}{14}$
$=\frac{7×1×5}{10×8×14}$
$=\frac{1}{32}$
$\frac{1}{4}×\frac{8}{9}÷\frac{9}{10}$
$=\frac{1}{4}×\frac{8}{9}×\frac{10}{9}$
$=\frac{1×8×10}{4×9×9}$
$=\frac{20}{81}$
$\frac{3}{10}÷18×\frac{4}{7}$
$=\frac{3}{10}×\frac{1}{18}×\frac{4}{7}$
$=\frac{3×1×4}{10×18×7}$
$=\frac{1}{105}$
$\frac{7}{5}×6÷\frac{14}{15}$
$=\frac{7}{5}×6×\frac{15}{14}$
$=\frac{7×6×15}{5×14}$
$=9$
$\frac{9}{22}÷\frac{3}{4}÷\frac{8}{33}$
$=\frac{9}{22}×\frac{4}{3}×\frac{33}{8}$
$=\frac{9×4×33}{22×3×8}$
$=\frac{9}{4}$