Question

20．计算下面各题
$\frac{2}{3}$×90                    
$\frac{25}{4}$×$\frac{8}{15}$                  
$\frac{3}{5}$×$\frac{5}{27}$×$\frac{3}{8}$
$\frac{2}{5}$÷$\frac{7}{15}$                      
9÷$\frac{1}{3}$                   
$\frac{7}{10}$÷8÷$\frac{14}{5}$．

Answer 1

分析 根据分数乘除法运算的计算法则计算即可求解．

解答 解：$\frac{2}{3}$×90=60                    

$\frac{25}{4}$×$\frac{8}{15}$=$\frac{10}{3}$                  

$\frac{3}{5}$×$\frac{5}{27}$×$\frac{3}{8}$
=$\frac{1}{9}$×$\frac{3}{8}$
=$\frac{1}{24}$

$\frac{2}{5}$÷$\frac{7}{15}$=$\frac{6}{7}$                      

9÷$\frac{1}{3}$=27                   

$\frac{7}{10}$÷8÷$\frac{14}{5}$
=$\frac{7}{80}$÷$\frac{14}{5}$
=$\frac{1}{32}$

点评 考查了分数乘除法运算，关键是熟练掌握计算法则正确进行计算．