1. 直接写出得数。
2.5×$\frac{6}{5}$=
$\frac{16}{7}$÷24=
45×$\frac{10}{9}$=
$\frac{3}{8}$×$\frac{9}{2}$=
$\frac{4}{7}$×$\frac{5}{6}$=
$\frac{5}{8}$÷$\frac{8}{5}$=
$\frac{11}{15}$×3=
0.9×$\frac{13}{54}$=
$\frac{8}{9}$÷3=
33×$\frac{3}{83}$=
4.5÷$\frac{3}{10}$=
$\frac{8}{17}$×0.5=

$2.5×\frac{6}{5}=3$
$\frac{16}{7}÷24=\frac{2}{21}$
$45×\frac{10}{9}=50$
$\frac{3}{8}×\frac{9}{2}=\frac{27}{16}$
$\frac{4}{7}×\frac{5}{6}=\frac{10}{21}$
$\frac{5}{8}÷\frac{8}{5}=\frac{25}{64}$
$\frac{11}{15}×3=\frac{11}{5}$
$0.9×\frac{13}{54}=\frac{13}{60}$
$\frac{8}{9}÷3=\frac{8}{27}$
$33×\frac{3}{83}=\frac{99}{83}$
$4.5÷\frac{3}{10}=15$
$\frac{8}{17}×0.5=\frac{4}{17}$

2. 在$◯$里填上“＞”“＜”或“=”。
$11×\frac{2}{9} ◯ \frac{11}{9}×2$
$82÷\frac{41}{5} ◯ \frac{1}{82}×\frac{41}{5}$
$\frac{3}{5}÷\frac{1}{5} ◯ \frac{3}{5}$
$\frac{7}{10}×\frac{1}{5} ◯ \frac{7}{10}+\frac{1}{5}$
$\frac{5}{7}-\frac{20}{49}÷\frac{4}{7} ◯ \frac{15}{49}×\frac{7}{4}$
$\frac{9}{7}+\frac{12}{7}×\frac{7}{9} ◯ 3×\frac{7}{9}$

$11×\frac{2}{9} \boldsymbol{=} \frac{11}{9}×2$
$82÷\frac{41}{5} \boldsymbol{＞} \frac{1}{82}×\frac{41}{5}$
$\frac{3}{5}÷\frac{1}{5} \boldsymbol{＞} \frac{3}{5}$
$\frac{7}{10}×\frac{1}{5} \boldsymbol{＜} \frac{7}{10}+\frac{1}{5}$
$\frac{5}{7}-\frac{20}{49}÷\frac{4}{7} \boldsymbol{＜} \frac{15}{49}×\frac{7}{4}$
$\frac{9}{7}+\frac{12}{7}×\frac{7}{9} \boldsymbol{＞} 3×\frac{7}{9}$

3. 用运算律进行简便计算。
$\frac{11}{14}×\frac{7}{15} - \frac{1}{7}÷\frac{15}{7}$
$\frac{7}{3}×12.5×\frac{15}{14}×0.8$
$( \frac{2}{51} + \frac{5}{34} )×6×17$

第一题
$\begin{aligned}\frac{11}{14}×\frac{7}{15} - \frac{1}{7}÷\frac{15}{7}&=\frac{11}{14}×\frac{7}{15} - \frac{1}{7}×\frac{7}{15}\\&=(\frac{11}{14}-\frac{1}{7})×\frac{7}{15}\\&=(\frac{11}{14}-\frac{2}{14})×\frac{7}{15}\\&=\frac{9}{14}×\frac{7}{15}\\&=\frac{3}{10}\end{aligned}$
第二题
$\begin{aligned}\frac{7}{3}×12.5×\frac{15}{14}×0.8&=(\frac{7}{3}×\frac{15}{14})×(12.5×0.8)\\&=\frac{5}{2}×10\\&=25\end{aligned}$
第三题
$\begin{aligned}(\frac{2}{51}+\frac{5}{34})×6×17&=\frac{2}{51}×6×17+\frac{5}{34}×6×17\\&=4+15\\&=19\end{aligned}$