一、口算。
$\frac{3}{8} ÷ \frac{3}{7} =$
$35 ÷ \frac{7}{15} =$
$9 ÷ \frac{1}{2} =$
$\frac{5}{6} ÷ \frac{7}{8} =$
$\frac{1}{12} ÷ \frac{5}{8} =$
$\frac{4}{9} ÷ \frac{8}{3} =$
$15 ÷ \frac{5}{7} =$
$3 ÷ \frac{6}{7} =$
$\frac{1}{2} ÷ \frac{2}{5} =$
$\frac{9}{4} ÷ \frac{1}{2} =$
$\frac{5}{4} ÷ \frac{12}{5} =$
$2 ÷ \frac{3}{5} =$
$\frac{8}{3} ÷ \frac{4}{3} =$
$16 ÷ \frac{8}{11} =$
$\frac{3}{8} ÷ \frac{8}{5} =$
$\frac{9}{5} ÷ \frac{2}{3} =$
$\frac{2}{9} ÷ \frac{3}{5} =$
$\frac{2}{3} ÷ \frac{1}{14} =$
$\frac{11}{2} ÷ \frac{5}{3} =$
$\frac{2}{3} ÷ \frac{5}{8} =$
$7 ÷ \frac{21}{25} =$

1.$\frac{7}{8}$
2.$75$
3.$18$
4.$\frac{20}{21}$
5.$\frac{2}{15}$
6.$\frac{1}{6}$
7.$21$
8.$\frac{7}{2}$
9.$\frac{5}{4}$
10.$\frac{9}{2}$
11.$\frac{25}{48}$
12.$\frac{10}{3}$
13.$2$
14.$22$
15.$\frac{15}{64}$
16.$\frac{27}{10}$
17.$\frac{10}{27}$
18.$\frac{28}{3}$
19.$\frac{33}{10}$
20.$\frac{16}{15}$
21.$\frac{25}{3}$

二、计算下面各题，能用简便算法的就用简便算法。
$\frac{6}{7} + ( \frac{7}{8} + \frac{1}{5} ) ÷ \frac{7}{5}$
$\frac{5}{6} + \frac{7}{9} × \frac{2}{7} × \frac{3}{4}$
$( \frac{5}{9} + \frac{4}{21} - \frac{3}{7} ) ÷ \frac{1}{63}$
$100 × \frac{98}{99}$
$\frac{4}{9} ÷ \frac{16}{3} + \frac{7}{12}$
$\frac{16}{9} × \frac{8}{11} - \frac{7}{11} ÷ \frac{9}{8}$

1.$1\frac{5}{8}$
2.$1$
3.$20$
4.$98\frac{98}{99}$
5.$\frac{2}{3}$
6.$\frac{8}{11}$