1 练算理
建议用时2分钟 评价：☆☆☆

$\frac{9}{16} ÷ 9 = \frac{9}{16} × \frac{1}{9} = \frac{(\quad)}{(\quad)}$
$\frac{8}{9} ÷ 4 = \frac{(\quad)}{(\quad)} ◯ \frac{(\quad)}{(\quad)} = \frac{(\quad)}{(\quad)}$
$14 ÷ \frac{7}{10} = 14 × \frac{10}{7} = (\quad)$
$\frac{8}{7} ÷ \frac{16}{21} = \frac{(\quad)}{(\quad)} ◯ \frac{(\quad)}{(\quad)} = \frac{(\quad)}{(\quad)}$

1. 1/16
8/9 × 1/4 = 2/9
20
8/7 × 21/16 = 3/2

$\frac{1}{3} ÷ \frac{4}{5} =$
$\frac{4}{3} ÷ \frac{3}{4} =$
$\frac{9}{8} ÷ \frac{5}{6} =$
$\frac{1}{6} ÷ 0.9 =$
$0 ÷ \frac{1}{100} =$
$\frac{3}{7} ÷ \frac{1}{3} =$
$\frac{21}{40} ÷ \frac{7}{8} =$
$\frac{13}{25} ÷ 13 =$
$13 ÷ \frac{2}{7} =$
$\frac{15}{16} ÷ 5 =$
$\frac{1}{8} ÷ \frac{5}{2} =$
$\frac{3}{8} ÷ \frac{6}{7} =$
$\frac{8}{15} ÷ \frac{2}{5} =$
$\frac{7}{26} ÷ \frac{21}{13} =$
$\frac{5}{33} ÷ \frac{5}{22} =$
$\frac{5}{48} ÷ 5 =$

2. 5/12
16/9
27/20
5/27
0
9/7
3/5
1/25
91/2
3/16
1/20
7/16
4/3
1/6
2/3
1/48

3 脱式计算（能简算的要简算） 建议用时6分钟 评价：☆☆☆
$18÷(1-\dfrac{5}{6})$
$9×\dfrac{9}{13}+\dfrac{9}{13}÷\dfrac{1}{9}$
$\dfrac{1}{5}+\dfrac{2}{9}÷\dfrac{5}{9}$
$\dfrac{5}{6}×\dfrac{5}{7}÷\dfrac{5}{9}$
$(\dfrac{1}{6}+\dfrac{3}{7}-\dfrac{5}{21})÷\dfrac{1}{42}$
$\dfrac{5}{12}÷[(\dfrac{3}{4}+\dfrac{1}{2})÷\dfrac{2}{3}]$
$\dfrac{3}{25}×(\dfrac{5}{7}÷\dfrac{3}{14})$
$36÷[(\dfrac{5}{6}-\dfrac{1}{3})×3]$
$(\dfrac{14}{15}×\dfrac{38}{39})÷(\dfrac{38}{15}×\dfrac{14}{39})$

3. 108
162/13
3/5
15/14
15
2/9
2/5
24
1