一、口算。
$\frac{5}{6} - \frac{3}{4} =$
$\frac{10}{3} × 60\% =$
$( \frac{3}{4} - \frac{7}{12} ) × 24 =$
$\frac{9}{2} ÷ 50\% =$
$15 ÷ \frac{5}{8} =$
$148\% + 5.2 + 0.52 =$
$\frac{5}{9} ÷ \frac{2}{3} =$
$\frac{1}{3} + \frac{5}{6} =$
$\frac{2}{3} × 0.25 ÷ \frac{3}{50} =$
$\frac{3}{8} - \frac{1}{6} =$
$50\% × \frac{2}{25} =$
$24 × ( \frac{3}{5} ÷ \frac{1}{5} ) =$
$34.2\% - 23\% =$
$\frac{3}{8} ÷ \frac{5}{32} =$
$\frac{7}{8} - \frac{5}{12} + \frac{1}{8} =$
$125 × \frac{4}{25} =$
$\frac{1}{2} ÷ \frac{3}{4} =$
$\frac{5}{8} × (1 - 20\%) =$
$\frac{5}{12} + \frac{1}{4} =$
$0.9 × \frac{5}{12} =$
$\frac{5}{7} - ( \frac{5}{7} - \frac{3}{7} ) =$

1.$\frac{1}{12}$ 2.$2$ 3.$4$ 4.$9$ 5.$24$ 6.$7.2$ 7.$\frac{5}{6}$ 8.$\frac{7}{6}$ 9.$\frac{25}{9}$ 10.$\frac{5}{24}$ 11.$\frac{1}{25}$ 12.$72$ 13.$0.112$ 14.$\frac{12}{5}$ 15.$\frac{7}{12}$ 16.$20$ 17.$\frac{2}{3}$ 18.$\frac{1}{2}$ 19.$\frac{2}{3}$ 20.$\frac{3}{8}$ 21.$\frac{3}{7}$

二、计算下面各题，能用简便算法的就用简便算法。
$( \frac{1}{2} - \frac{1}{3} + \frac{1}{4} ) × 48$
$( \frac{3}{8} - \frac{3}{8} ÷ \frac{8}{3} ) × \frac{16}{9}$
$\frac{3}{5} × 8.8 + 0.6 × \frac{1}{5} + 60\%$
$\frac{99}{100} ÷ \frac{1}{2} ÷ \frac{2}{3} ÷ \frac{3}{4}$
$50\% × 3.5 - \frac{1}{2} × 1.5$
$7.24 × \frac{3}{5} - 2.24 × 60\%$

1.$20$ 2.$\frac{5}{12}$ 3.$6$ 4.$\frac{99}{25}$ 5.$1$ 6.$3$