1.直接写出得数。
$\frac{3}{4} × \frac{2}{3} =$
$\frac{7}{10} × \frac{5}{7} =$
$\frac{5}{4} × \frac{2}{5} =$
$\frac{4}{5} × \frac{5}{16} =$
$34 × \frac{3}{17} =$
$\frac{4}{9} × \frac{3}{8} =$
$\frac{2}{3} × \frac{5}{4} =$
$\frac{9}{8} × \frac{2}{3} =$
$\frac{1}{5} × \frac{3}{4} =$
$\frac{7}{8} × \frac{16}{21} =$
$\frac{3}{2} × \frac{5}{9} =$
$\frac{7}{9} × \frac{3}{14} =$
$\frac{1}{42} × \frac{7}{6} =$
$\frac{4}{27} × \frac{9}{16} =$
$\frac{1}{5} × \frac{25}{6} =$
$\frac{1}{4} × \frac{3}{5} =$
$\frac{4}{3} × \frac{5}{16} =$
$5 × \frac{5}{8} =$

$\frac{3}{4} × \frac{2}{3} = \frac{1×1}{2×1} = \frac{1}{2}$
$\frac{7}{10} × \frac{5}{7} = \frac{1×1}{2×1} = \frac{1}{2}$
$\frac{5}{4} × \frac{2}{5} = \frac{1×1}{2×1} = \frac{1}{2}$
$\frac{4}{5} × \frac{5}{16} = \frac{1×1}{1×4} = \frac{1}{4}$
$34 × \frac{3}{17} = 2×3 = 6$
$\frac{4}{9} × \frac{3}{8} = \frac{1×1}{3×2} = \frac{1}{6}$
$\frac{2}{3} × \frac{5}{4} = \frac{1×5}{3×2} = \frac{5}{6}$
$\frac{9}{8} × \frac{2}{3} = \frac{3×1}{4×1} = \frac{3}{4}$
$\frac{1}{5} × \frac{3}{4} = \frac{1×3}{5×4} = \frac{3}{20}$
$\frac{7}{8} × \frac{16}{21} = \frac{1×2}{1×3} = \frac{2}{3}$
$\frac{3}{2} × \frac{5}{9} = \frac{1×5}{2×3} = \frac{5}{6}$
$\frac{7}{9} × \frac{3}{14} = \frac{1×1}{3×2} = \frac{1}{6}$
$\frac{1}{42} × \frac{7}{6} = \frac{1×1}{6×6} = \frac{1}{36}$
$\frac{4}{27} × \frac{9}{16} = \frac{1×1}{3×4} = \frac{1}{12}$
$\frac{1}{5} × \frac{25}{6} = \frac{1×5}{1×6} = \frac{5}{6}$
$\frac{1}{4} × \frac{3}{5} = \frac{1×3}{4×5} = \frac{3}{20}$
$\frac{4}{3} × \frac{5}{16} = \frac{1×5}{3×4} = \frac{5}{12}$
$5 × \frac{5}{8} = \frac{5×5}{8} = \frac{25}{8}$

2.看图列式计算。


(1)
列式：
(2)
列式：
(3)


列式：
(4)
列式：

(1) $\frac{2}{3} × \frac{1}{2} = \frac{1}{3}$
(2) $\frac{1}{2} × \frac{1}{3} = \frac{1}{6}$
(3) $\frac{2}{3} × \frac{2}{5} = \frac{4}{15}$
(4) $\frac{3}{5} × \frac{2}{3} = \frac{2}{5}$