Question

11．用簡(jiǎn)便方法計(jì)算下面各題．
0.75+$\frac{5}{8}$+$\frac{1}{4}$+0.375                    
356×$\frac{6}{7}$+420÷$\frac{7}{6}$+$\frac{6}{7}$
（$\frac{3}{8}$+$\frac{2}{3}$）÷$\frac{1}{24}$                      
32.48-（39.5+2.48）

Answer 1

分析 ①把分?jǐn)?shù)化成小數(shù)，根據(jù)加法交換律及結(jié)合律計(jì)算；
②420÷$\frac{7}{6}$=420×$\frac{6}{7}$，根據(jù)乘法分配律進(jìn)行計(jì)算；
③除以$\frac{1}{24}$，等于乘4，再根據(jù)乘法分配律進(jìn)行計(jì)算；
④根據(jù)減法性質(zhì)進(jìn)行計(jì)算．

解答 解：①0.75+$\frac{5}{8}$+$\frac{1}{4}$+0.375    
=0.75+0.625+0.25+0.375
=（0.75+0.25）+（0.625+0.375）
=1+1
=2
              
②356×$\frac{6}{7}$+420÷$\frac{7}{6}$+$\frac{6}{7}$
=356×$\frac{6}{7}$+420×$\frac{6}{7}$+$\frac{6}{7}$
=（356+420+1）×$\frac{6}{7}$
=777×$\frac{6}{7}$
=666

③（$\frac{3}{8}$+$\frac{2}{3}$）÷$\frac{1}{24}$   
=（$\frac{3}{8}$+$\frac{2}{3}$）×24
=$\frac{3}{8}$×24+$\frac{2}{3}$×24
=9+16
=25   
                   
④32.48-（39.5+2.48）
=32.48-39.5-2.48
=32.48-2.48-39.5
=-9.5

點(diǎn)評(píng) 完成本題要注意分析式中數(shù)據(jù)，運(yùn)用合適的簡(jiǎn)便方法計(jì)算．