1. 直接写出得数。（20☆）
$4÷\frac{2}{3}=$
$6÷\frac{6}{17}=$
$3÷\frac{3}{19}=$
$1÷\frac{3}{11}=$
$19÷\frac{19}{14}=$
$16÷\frac{32}{7}=$
$5÷\frac{15}{16}=$
$35÷\frac{7}{9}=$
$6÷\frac{2}{21}=$
$9÷\frac{3}{8}=$
$0÷\frac{3}{19}=$
$5÷\frac{1}{3}=$
$\frac{8}{5}÷\frac{4}{5}=$
$\frac{7}{6}÷\frac{14}{3}=$
$\frac{5}{4}÷\frac{3}{2}=$
$\frac{6}{7}÷\frac{3}{14}=$
$\frac{9}{10}÷\frac{3}{5}=$
$\frac{13}{14}÷\frac{5}{7}=$
$\frac{3}{5}÷\frac{3}{10}=$
$\frac{4}{3}÷\frac{8}{9}=$

$4÷\frac{2}{3}=6$
$6÷\frac{6}{17}=17$
$3÷\frac{3}{19}=19$
$1÷\frac{3}{11}=\frac{11}{3}$
$19÷\frac{19}{14}=14$
$16÷\frac{32}{7}=\frac{7}{2}$
$5÷\frac{15}{16}=\frac{16}{3}$
$35÷\frac{7}{9}=45$
$6÷\frac{2}{21}=63$
$9÷\frac{3}{8}=24$
$0÷\frac{3}{19}=0$
$5÷\frac{1}{3}=15$
$\frac{8}{5}÷\frac{4}{5}=2$
$\frac{7}{6}÷\frac{14}{3}=\frac{1}{4}$
$\frac{5}{4}÷\frac{3}{2}=\frac{5}{6}$
$\frac{6}{7}÷\frac{3}{14}=4$
$\frac{9}{10}÷\frac{3}{5}=\frac{3}{2}$
$\frac{13}{14}÷\frac{5}{7}=\frac{13}{10}$
$\frac{3}{5}÷\frac{3}{10}=2$
$\frac{4}{3}÷\frac{8}{9}=\frac{3}{2}$

2. 在○里填上“＞”“＜”或“=”。(16☆)
$\frac{8}{11} ÷ 2 ◯ \frac{8}{11}$
$\frac{8}{11} ÷ 1 ◯ \frac{8}{11}$
$\frac{8}{11} ÷ \frac{1}{2} ◯ \frac{8}{11}$
$\frac{8}{11} ÷ \frac{1}{2} ◯ \frac{8}{11} × 2$
$\frac{1}{4} ÷ 3 ◯ \frac{1}{4} × 3$
$\frac{2}{5} ÷ 2 ◯ 2 ÷ \frac{2}{5}$
$\frac{7}{12} ÷ \frac{1}{7} ◯ \frac{7}{12} × \frac{1}{2}$
$\frac{5}{11} ÷ 2 ◯ \frac{5}{11} ÷ \frac{1}{2}$

$\frac{8}{11} ÷ 2 ＜ \frac{8}{11}$
$\frac{8}{11} ÷ 1 = \frac{8}{11}$
$\frac{8}{11} ÷ \frac{1}{2} ＞ \frac{8}{11}$
$\frac{8}{11} ÷ \frac{1}{2} = \frac{8}{11} × 2$
$\frac{1}{4} ÷ 3 ＜ \frac{1}{4} × 3$
$\frac{2}{5} ÷ 2 ＜ 2 ÷ \frac{2}{5}$
$\frac{7}{12} ÷ \frac{1}{7} ＞ \frac{7}{12} × \frac{1}{2}$
$\frac{5}{11} ÷ 2 ＜ \frac{5}{11} ÷ \frac{1}{2}$

3. 下面的计算对吗？对的画“√”，错的画“×”，并改正。(8☆)
(1) $\frac{4}{15} ÷ \frac{5}{12} = \frac{\overset{1}{\cancel{4}}}{\underset{3}{\cancel{15}}} × \frac{\overset{1}{\cancel{5}}}{\underset{3}{\cancel{12}}} = \frac{1}{9}$ () 改正：
(2) $2.5 ÷ \frac{3}{5} = \frac{\cancel{2.5}}{0.5} ÷ \frac{3}{\underset{1}{\cancel{5}}} = 1.5$ () 改正：

(1) × $\frac{4}{15}÷\frac{5}{12}=\frac{4}{15}×\frac{12}{5}=\frac{16}{25}$
(2) × $2.5÷\frac{3}{5}=2.5×\frac{5}{3}=\frac{25}{6}$

4. 计算下面各题。(6☆)
$36÷\frac{9}{7}+\frac{4}{3}÷\frac{5}{6}$
$\frac{3}{10}÷\frac{8}{15}÷\frac{9}{16}$
$(\frac{1}{4}+\frac{1}{7})÷\frac{5}{14}$

$36÷\frac{9}{7}+\frac{4}{3}÷\frac{5}{6}=29\frac{3}{5}$
$\frac{3}{10}÷\frac{8}{15}÷\frac{9}{16}=1$
$(\frac{1}{4}+\frac{1}{7})÷\frac{5}{14}=\frac{11}{10}$