1. 口算。（建议用时3分钟）
$\frac{3}{19} × 57 =$
$\frac{1}{2} + \frac{1}{3} =$
$80\% × \frac{5}{8} =$
$\frac{5}{6} ÷ 10 =$
$20\% ÷ \frac{1}{3} =$
$2 - 1\frac{3}{8} =$
$12 × \frac{2}{3} =$
$\frac{8}{9} ÷ 12 =$
$18 ÷ \frac{9}{20} =$
$\frac{9}{11} × 3 =$
$\frac{3}{20} × \frac{4}{9} =$
$\frac{1}{6} ÷ \frac{2}{9} =$
$\frac{4}{15} × \frac{15}{16} =$
$7 × \frac{5}{14} =$
$\frac{9}{40} × \frac{2}{3} =$
$12 ÷ \frac{1}{5} =$
$60\% × \frac{1}{3} =$
$27 ÷ \frac{9}{20} =$
$6 ÷ \frac{3}{5} =$
$\frac{6}{11} ÷ 2 =$

1. $9$
$\frac{5}{6}$
$\frac{1}{2}$
$\frac{1}{12}$
$\frac{3}{5}$
$\frac{5}{8}$
$8$
$\frac{2}{27}$
$40$
$\frac{27}{11}$
$\frac{1}{15}$
$\frac{3}{4}$
$\frac{1}{4}$
$\frac{5}{2}$
$\frac{3}{20}$
$60$
$0.2$
$60$
$10$
$\frac{3}{11}$

2. 在○里填上“＞”“＜”或“=”。（建议用时2分钟）
-5○0
$-\dfrac{7}{11}$○$-\dfrac{9}{11}$
$5-10$○$10-15$
$\dfrac{15}{19}÷5$○$\dfrac{1}{6}$
$\dfrac{5}{6}×\dfrac{4}{9}$○$\dfrac{1}{3}$
$\dfrac{6}{13}×\dfrac{1}{3}$○$\dfrac{6}{16}÷\dfrac{1}{3}$

2. $＜$
$＞$
$=$
$＜$
$＞$
$＜$

3. 计算下面各题，能用简便算法的就用简便算法。（建议用时2分钟）
$\frac{8}{13}×\frac{2}{7}÷\frac{4}{91}$
$(\frac{3}{4}+\frac{13}{25})×100$
$\frac{5}{13}×\frac{9}{10}+\frac{5}{13}×10\%$

3. $4$
$127$
$\frac{5}{13}$

4. 解决问题。(建议用时3分钟)
静静在计算一个数除以$\frac{3}{5}$时，糊涂地当成了乘法计算，得出的结果是$\frac{21}{10}$。正确的结果是多少？

4. $\frac{21}{10} ÷ \frac{3}{5} = \frac{7}{2}$ $\frac{7}{2} ÷ \frac{3}{5} = \frac{35}{6}$