1. 直接写出得数。(20☆)
$\frac{4}{7}×2=$ $\frac{4}{9}×4=$ $\frac{4}{5}×3=$ $\frac{5}{6}×7=$
$\frac{3}{8}×5=$ $\frac{3}{5}×2=$ $\frac{7}{9}×6=$ $\frac{3}{5}×5=$
$\frac{5}{9}×3=$ $\frac{3}{8}×4=$ $\frac{1}{18}×9=$ $\frac{17}{36}×24=$
$\frac{5}{12}×4=$ $\frac{4}{15}×5=$ $\frac{5}{6}×3=$ $\frac{4}{15}×6=$
$\frac{12}{21}×3=$ $\frac{4}{57}×19=$ $\frac{3}{7}×7=$ $\frac{7}{24}×6=$

$\frac{8}{7}$ $\frac{16}{9}$ $\frac{12}{5}$ $\frac{35}{6}$
$\frac{15}{8}$ $\frac{6}{5}$ $\frac{14}{3}$ $3$
$\frac{5}{3}$ $\frac{3}{2}$ $\frac{1}{2}$ $\frac{34}{3}$
$\frac{5}{3}$ $\frac{4}{3}$ $\frac{5}{2}$ $\frac{8}{5}$
$\frac{12}{7}$ $\frac{4}{3}$ $3$ $\frac{7}{4}$

2. 填一填。(10☆)
(1) $\frac{1}{4}+\frac{1}{4}+\frac{1}{4}+\frac{1}{4}=\frac{1}{4}×(\quad)=(\quad)$ $\frac{3}{5}+\frac{3}{5}+\frac{3}{5}+\frac{3}{5}+\frac{3}{5}=\frac{3}{5}×(\quad)=(\quad)$
(2) $\frac{7}{50}\mathrm{kg}=(\quad)\mathrm{g}$ $\frac{9}{40}\mathrm{m}^3=(\quad)\mathrm{dm}^3$ $\frac{1}{6}\mathrm{小时}=(\quad)\mathrm{分钟}$
$\frac{3}{4}\mathrm{天}=(\quad)\mathrm{小时}$ $\frac{7}{25}\mathrm{dm}^3=(\quad)\mathrm{cm}^3$ $\frac{3}{40}\mathrm{dm}^2=(\quad)\mathrm{cm}^2$

2.(1)4 1 5 3
(2)140 225 10 18 280 7.5

3. 在○里填上“＞”“＜”或“=”。(12☆)
$\frac{4}{9}×9 ◯ \frac{4}{5}×5$
$\frac{3}{4}×8 ◯ \frac{5}{6}×5$
$\frac{9}{14}×7 ◯ \frac{4}{15}×5$
$\frac{8}{27}×9 ◯ \frac{4}{3}×2$
$\frac{4}{21}×7 ◯ \frac{5}{18}×6$
$\frac{5}{6}×4 ◯ \frac{4}{7}×3$

= ＞ ＞
= ＜ ＞

4. 下面各题算得对吗？把不对的改正过来。(8☆)
$3×\frac{3}{5}=\frac{1}{3}×\frac{1}{5}=\frac{1}{5}$
$\frac{5}{14}×\frac{4}{7}=\frac{5}{7}×\frac{2}{7}=\frac{7}{7}=1$
用时：分钟 ★共得：☆/50 ☆

× $3×\frac{3}{5}=\frac{9}{5}$
× $\frac{5}{14}×\frac{4}{7}=\frac{10}{49}$