一、口算。
$\frac{4}{5} ÷ 100 =$
$7 ÷ \frac{5}{7} =$
$\frac{2}{5} × \frac{3}{5} ÷ \frac{1}{2} =$
$0.8 × \frac{3}{2} =$
$\frac{3}{4} + \frac{3}{8} =$
$1 ÷ \frac{3}{5} × \frac{5}{3} =$
$\frac{1}{8} + \frac{7}{12} =$
$\frac{5}{6} ÷ \frac{1}{30} =$
$\frac{5}{4} × \frac{2}{3} × \frac{4}{5} =$
$\frac{3}{4} ÷ \frac{5}{6} =$
$\frac{4}{5} - \frac{3}{10} =$
$\frac{3}{16} × \frac{4}{15} ÷ \frac{9}{10} =$
$\frac{9}{10} - \frac{5}{6} =$
$\frac{1}{100} ÷ \frac{1}{10} =$
$\frac{9}{10} ÷ \frac{3}{8} ÷ \frac{1}{4} =$
$\frac{5}{6} × 1.2 =$
$\frac{5}{9} ÷ \frac{5}{6} =$
$\frac{2}{3} × \frac{9}{4} × \frac{1}{2} =$
$\frac{8}{9} ÷ \frac{8}{9} =$
$\frac{5}{4} × 4.8 =$
$\frac{2}{3} × 2 ÷ \frac{2}{3} =$

$\frac{1}{125}$
$\frac{49}{5}$
$\frac{12}{25}$
$1.2$
$\frac{9}{8}$
$\frac{25}{9}$
$\frac{17}{24}$
$25$
$\frac{2}{3}$
$\frac{9}{10}$
$\frac{1}{2}$
$\frac{1}{18}$
$\frac{1}{15}$
$\frac{1}{10}$
$\frac{48}{5}$
$1$
$\frac{2}{3}$
$\frac{3}{4}$
$1$
$6$
$2$

二、计算下面各题，能用简便算法的就用简便算法。
$(\frac{3}{4} - \frac{3}{5}) ÷ \frac{7}{10}$
$4 ÷ \frac{4}{7} - \frac{4}{7} ÷ 4$
$30 × (\frac{3}{5} + \frac{1}{6} - \frac{4}{15})$
$(\frac{1}{2} + \frac{7}{10}) × \frac{2}{5} + 2$
$\frac{8}{49} ÷ [\frac{9}{8} - (\frac{1}{8} + \frac{3}{7})]$
$(\frac{2}{11} + \frac{2}{11} + \frac{2}{11} + \frac{2}{11}) × 2.5$

$\frac{3}{14}$
$6\frac{6}{7}$
$15$
$2\frac{12}{25}$
$\frac{2}{7}$
$\frac{20}{11}$