1. 直接写出得数。(16☆)
$\frac{4}{7}×2=$ $\frac{4}{9}×4=$ $\frac{4}{5}×3=$ $\frac{5}{6}×7=$
$\frac{3}{8}×5=$ $\frac{3}{5}×2=$ $\frac{7}{9}×6=$ $\frac{3}{5}×5=$
$\frac{5}{9}×3=$ $\frac{3}{8}×4=$ $\frac{1}{18}×9=$ $\frac{17}{36}×24=$
$4×\frac{5}{8}=$ $7×\frac{5}{14}=$ $20×\frac{1}{2}=$ $8×\frac{4}{9}=$
$3×\frac{5}{21}=$ $12×\frac{7}{36}=$ $18×\frac{4}{9}=$ $12×\frac{5}{6}=$
$\frac{3}{8}×\frac{4}{5}=$ $\frac{1}{9}×\frac{1}{5}=$ $\frac{1}{8}×\frac{4}{7}=$ $\frac{5}{3}×\frac{7}{6}=$
$\frac{1}{4}×\frac{1}{4}=$ $\frac{3}{7}×\frac{3}{5}=$ $\frac{2}{7}×\frac{4}{13}=$ $\frac{1}{3}×\frac{2}{9}=$
$\frac{8}{3}×\frac{3}{4}=$ $\frac{7}{9}×\frac{3}{4}=$ $\frac{2}{5}×\frac{15}{8}=$ $\frac{2}{3}×\frac{9}{10}=$

1. $\frac{8}{7}$ $\frac{16}{9}$ $\frac{12}{5}$ $\frac{35}{6}$
$\frac{15}{8}$ $\frac{6}{5}$ $\frac{14}{3}$ $3$
$\frac{5}{3}$ $\frac{3}{2}$ $\frac{1}{2}$ $\frac{34}{3}$
$\frac{5}{2}$ $\frac{5}{2}$ $10$ $\frac{32}{9}$
$\frac{5}{7}$ $\frac{7}{3}$ $8$ $10$
$\frac{3}{10}$ $\frac{1}{45}$ $\frac{1}{14}$ $\frac{35}{18}$
$\frac{1}{16}$ $\frac{9}{35}$ $\frac{8}{91}$ $\frac{2}{27}$
$2$ $\frac{7}{12}$ $\frac{3}{4}$ $\frac{3}{5}$

2. 解方程。(24☆)
$x+\frac{1}{4}=\frac{2}{3}$
$1.2x-3×0.6=7.8$
$5x÷4.5=2.6$
$x-\frac{1}{9}=\frac{7}{9}$
$3.6x=72$
$12x÷6=8$

2. $x=\frac{5}{12}$ $x=8$ $x=2.34$
$x=\frac{8}{9}$ $x=20$ $x=4$

3. 计算下面各题,能简算的要简算。(12☆)
$\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+\frac{1}{56}+\frac{1}{72}$
$51+52+53+54+55+56+57+58+59+60$

3. $\frac{8}{9}$ 555