3. 看图列式计算。
(1)
(2)

(1)
$40×\frac{3}{5}=24(\mathrm{m})$
答：所求长度是24m。
(2)
$24÷\frac{3}{5}=40(\mathrm{m})$
答：总长度是40m。

4.直接写得数。
$1÷ \frac{5}{6}=$
$5÷ \frac{10}{11}=$
$\frac{1}{3}×0.15=$
$0.35÷ \frac{5}{4}=$
$\frac{8}{7}÷4=$
$\frac{7}{8}× \frac{3}{14}=$
$\frac{5}{12}÷ \frac{4}{15}=$
$\frac{3}{5}÷ \frac{3}{4}=$
$\frac{9}{10}÷ \frac{3}{7}=$
$1÷8× \frac{1}{8}=$
$\frac{1}{2}× \frac{1}{3}÷ \frac{1}{3}× \frac{1}{2}=$

$1÷ \frac{5}{6}=\frac{6}{5}$
$5÷ \frac{10}{11}=\frac{11}{2}$
$\frac{1}{3}×0.15=0.05$
$0.35÷ \frac{5}{4}=\frac{7}{25}$
$\frac{8}{7}÷4=\frac{2}{7}$
$\frac{7}{8}× \frac{3}{14}=\frac{3}{16}$
$\frac{5}{12}÷ \frac{4}{15}=\frac{25}{16}$
$\frac{3}{5}÷ \frac{3}{4}=\frac{4}{5}$
$\frac{9}{10}÷ \frac{3}{7}=\frac{21}{10}$
$1÷8× \frac{1}{8}=\frac{1}{64}$
$\frac{1}{2}× \frac{1}{3}÷ \frac{1}{3}× \frac{1}{2}=\frac{1}{4}$

5.计算下面各题。
$\frac{37}{3}×\frac{8}{37}÷\frac{2}{3}$
$\frac{35}{11}÷\frac{28}{19}÷\frac{19}{22}$
$\frac{7}{9}+\frac{1}{4}×\frac{8}{9}$
$(\frac{4}{5}+\frac{3}{10})÷\frac{3}{10}$
$\frac{6}{7}×\frac{1}{11}+\frac{1}{7}÷11$
$\frac{1}{4}÷(\frac{4}{5}-\frac{1}{2})$

$\frac{37}{3}×\frac{8}{37}÷\frac{2}{3}$
$= \frac{8}{3} × \frac{3}{2}$
$= 4$
$\frac{35}{11}÷\frac{28}{19}÷\frac{19}{22}$
$= \frac{35}{11} × \frac{19}{28} × \frac{22}{19}$
$= \frac{5}{2}$
$\frac{7}{9}+\frac{1}{4}×\frac{8}{9}$
$= \frac{7}{9} + \frac{2}{9}$
$= 1$
$(\frac{4}{5}+\frac{3}{10})÷\frac{3}{10}$
$= (\frac{8}{10}+\frac{3}{10}) × \frac{10}{3}$
$= \frac{11}{10} × \frac{10}{3}$
$= \frac{11}{3}$
$\frac{6}{7}×\frac{1}{11}+\frac{1}{7}÷11$
$= \frac{6}{7}×\frac{1}{11}+\frac{1}{7}×\frac{1}{11}$
$= (\frac{6}{7}+\frac{1}{7}) × \frac{1}{11}$
$= \frac{1}{11}$
$\frac{1}{4}÷(\frac{4}{5}-\frac{1}{2})$
$= \frac{1}{4} ÷ \frac{3}{10}$
$= \frac{5}{6}$