1. 直接写出得数。
$24 × \frac{5}{8} =$
$\frac{3}{5} × 10 =$
$\frac{5}{12} × \frac{4}{5} =$
$3 × \frac{5}{6} =$
$\frac{8}{7} × 42 =$
$\frac{1}{3} + \frac{1}{6} =$
$5.5 × \frac{1}{11} =$
$4.8 × \frac{8}{3} =$
$\frac{8}{5} × \frac{35}{4} =$
$\frac{5}{18} × 12 =$
$\frac{12}{11} × \frac{44}{3} =$
$1 - \frac{3}{20} =$
$7 × \frac{4}{21} =$
$\frac{5}{6} × 7.2 =$
$\frac{4}{7} × \frac{7}{12} × \frac{3}{5} =$
$\frac{5}{3} × \frac{5}{7} × 3 =$

$24 × \frac{5}{8} = 15$
$\frac{3}{5} × 10 = 6$
$\frac{5}{12} × \frac{4}{5} = \frac{1}{3}$
$3 × \frac{5}{6} = \frac{5}{2}$
$\frac{8}{7} × 42 = 48$
$\frac{1}{3} + \frac{1}{6} = \frac{1}{2}$
$5.5 × \frac{1}{11} = 0.5$
$4.8 × \frac{8}{3} = 12.8$
$\frac{8}{5} × \frac{35}{4} = 14$
$\frac{5}{18} × 12 = \frac{10}{3}$
$\frac{12}{11} × \frac{44}{3} = 16$
$1 - \frac{3}{20} = \frac{17}{20}$
$7 × \frac{4}{21} = \frac{4}{3}$
$\frac{5}{6} × 7.2 = 6$
$\frac{4}{7} × \frac{7}{12} × \frac{3}{5} = \frac{1}{5}$
$\frac{5}{3} × \frac{5}{7} × 3 = \frac{25}{7}$

2.填一填。
$\frac{5}{6} × \frac{4}{11} = \frac{4}{11} ×$
$(\frac{3}{4} × a) × b = \frac{3}{4} × (\_\_\_\_\_\_)$
$a × \frac{7}{8} + 3 × \frac{7}{8} = (a +$ $) ×$
$\frac{4}{27} × (a +$ $) = \frac{4}{27} × a +$ $× b$

$\frac{5}{6} × \frac{4}{11} = \frac{4}{11} × \underline{\frac{5}{6}}$
$(\frac{3}{4} × a) × b = \frac{3}{4} × (\underline{a} × \underline{b})$
$a × \frac{7}{8} + 3 × \frac{7}{8} = (a + \underline{3}) × \underline{\frac{7}{8}}$
$\frac{4}{27} × (a + \underline{b}) = \frac{4}{27} × a + \underline{\frac{4}{27}} × b$

3. 用运算律进行简便计算。
$\frac{5}{6} × \frac{5}{9} + \frac{5}{9} × \frac{1}{6}$
$( \frac{1}{3} + \frac{1}{4} ) × 2.4$
$\frac{3}{8} - \frac{1}{6} × \frac{3}{8}$

$\frac{5}{6} × \frac{5}{9} + \frac{5}{9} × \frac{1}{6}$
$=\frac{5}{9}×(\frac{5}{6}+\frac{1}{6})$
$=\frac{5}{9}×1$
$=\frac{5}{9}$
$( \frac{1}{3} + \frac{1}{4} ) × 2.4$
$=\frac{1}{3}×2.4 + \frac{1}{4}×2.4$
$=0.8 + 0.6$
$=1.4$
$\frac{3}{8} - \frac{1}{6} × \frac{3}{8}$
$=\frac{3}{8}×(1 - \frac{1}{6})$
$=\frac{3}{8}×\frac{5}{6}$
$=\frac{5}{16}$

里最大能填多少？
$\frac{6}{11}×\frac{□}{5}＜1$
$\frac{□}{4}×\frac{8}{9}＜\frac{3}{4}$
$\frac{5}{12}×\frac{3}{□}＞\frac{5}{24}$
反思 我错了（）道题。
自我评价：

$\frac{6}{11}×\frac{□}{5} ＜ 1$
$6×□ ＜ 55$
里最大能填9。
$\frac{□}{4}×\frac{8}{9} ＜ \frac{3}{4}$
$8×□ ＜ 27$
里最大能填3。
$\frac{5}{12}×\frac{3}{□} ＞ \frac{5}{24}$
$□ ＜ 6$
里最大能填5。
反思 我错了（0）道题。
自我评价：计算准确，掌握牢固。