1. 直接写出得数。
$10÷\frac{5}{7}=$
$\frac{3}{4}÷12=$
$\frac{5}{6}÷\frac{7}{12}=$
$4÷\frac{8}{11}=$
$120÷\frac{5}{6}=$
$\frac{2}{15}÷\frac{6}{18}=$
$\frac{4}{7}÷\frac{22}{5}=$
$\frac{1}{3}÷\frac{1}{33}=$
$48÷\frac{4}{9}=$
$\frac{7}{25}÷\frac{21}{5}=$
$36÷\frac{4}{9}=$
$\frac{12}{21}÷6=$

$10÷\frac{5}{7}=14$
$\frac{3}{4}÷12=\frac{1}{16}$
$\frac{5}{6}÷\frac{7}{12}=\frac{10}{7}$
$4÷\frac{8}{11}=\frac{11}{2}$
$120÷\frac{5}{6}=144$
$\frac{2}{15}÷\frac{6}{18}=\frac{2}{5}$
$\frac{4}{7}÷\frac{22}{5}=\frac{10}{77}$
$\frac{1}{3}÷\frac{1}{33}=11$
$48÷\frac{4}{9}=108$
$\frac{7}{25}÷\frac{21}{5}=\frac{1}{15}$
$36÷\frac{4}{9}=81$
$\frac{12}{21}÷6=\frac{2}{21}$

2. 递等式计算。
$\frac{5}{7}÷\frac{5}{6}÷\frac{13}{28}$
$\frac{5}{13}×26÷\frac{3}{5}$
$\frac{7}{20}÷(\frac{7}{12}÷\frac{1}{2})$
$\frac{7}{9}÷\frac{5}{12}÷\frac{7}{18}$

$\frac{5}{7}÷\frac{5}{6}÷\frac{13}{28}=\frac{24}{13}$
$\frac{5}{13}×26÷\frac{3}{5}=\frac{50}{3}$
$\frac{7}{20}÷(\frac{7}{12}÷\frac{1}{2})=\frac{3}{10}$
$\frac{7}{9}÷\frac{5}{12}÷\frac{7}{18}=\frac{24}{5}$

3. 求下列图形的周长和面积。
(1)
(2)

(1)周长:$2×3.14×2=12.56(\mathrm{cm})$
面积:$3.14×2^2=12.56(\mathrm{cm}^2)$
(2)周长:$3.14×6=18.84(\mathrm{cm})$
面积:$3.14×(\frac{6}{2})^2=28.26(\mathrm{cm}^2)$