1. 直接写出得数。
实际用时：分钟
$\frac{4}{15}÷\frac{2}{3}=$
$\frac{1}{2}÷\frac{2}{3}=$
$\frac{7}{9}-\frac{4}{15}=$
$10÷\frac{5}{7}=$
$5-\frac{3}{4}=$
$\frac{11}{7}-\frac{15}{14}=$
$2-\frac{4}{15}=$
$\frac{5}{18}÷\frac{10}{27}=$
$30÷\frac{5}{6}=$
$\frac{8}{55}÷\frac{4}{5}=$
$\frac{5}{6}÷\frac{11}{12}=$
$\frac{3}{8}×\frac{8}{9}=$
$1-\frac{11}{12}=$
$\frac{4}{5}÷\frac{1}{2}=$
$\frac{3}{4}×\frac{16}{25}=$
$\frac{1}{2}÷\frac{3}{4}=$
$\frac{5}{4}-\frac{1}{3}=$
$\frac{6}{11}÷\frac{2}{3}=$
$\frac{10}{9}÷\frac{9}{7}=$
$\frac{7}{12}×\frac{9}{14}=$
$\frac{2}{5}÷\frac{3}{5}=$
$\frac{9}{10}÷\frac{4}{5}=$
$\frac{3}{5}-\frac{1}{2}=$
$\frac{3}{4}×\frac{12}{5}=$

1. $\frac{2}{5}$ $\frac{26}{15}$ $\frac{1}{12}$ $\frac{70}{81}$
$\frac{3}{4}$ $\frac{3}{4}$ $\frac{8}{5}$ $\frac{3}{8}$
$\frac{23}{45}$ 36 $\frac{12}{25}$ $\frac{2}{3}$
14 $\frac{2}{11}$ $\frac{2}{3}$ $\frac{9}{8}$
$\frac{17}{4}$ $\frac{10}{11}$ $\frac{11}{12}$ $\frac{1}{10}$
$\frac{1}{2}$ $\frac{1}{3}$ $\frac{9}{11}$ $\frac{9}{5}$

2. 计算下面各题。
$11 - \frac{5}{13} - \frac{8}{13}$
$\frac{1}{12} + \frac{1}{4} + \frac{5}{12} + \frac{3}{4}$
$\frac{1}{6} - ( \frac{13}{15} - \frac{5}{6} )$

2. 10 $\frac{3}{2}$ $\frac{2}{15}$

3. 求直径或半径。
$\begin{cases} r=1.2\ \mathrm{cm} \\ d= \end{cases}$
$\begin{cases} r= \\ d=6.8\ \mathrm{dm} \end{cases}$
$\begin{cases} d=\dfrac{4}{5}\ \mathrm{m} \\ r= \end{cases}$

3. 2.4 cm 3.4 dm $\frac{2}{5}$ m

$\frac{1}{2},\frac{1}{4},\frac{1}{8},\frac{1}{16},(\quad),\frac{1}{64}°$

【思维提升】$\frac{1}{32}$