Question

14．計(jì)算下面各題，能簡算的要簡算．
19.5÷0.25÷0.4        
0.36÷[（6.1-4.6）×0.8]
（45.9-32.7）÷8÷0.125
59.5÷0.25+70                   
 6.73×5.8+0.42×67.3．

Answer 1

分析 ①根據(jù)除法的性質(zhì)計(jì)算即可．
②首先計(jì)算小括號里面的減法，然后計(jì)算中括號里面的乘法，最后計(jì)算中括號外面的除法即可．
③首先計(jì)算小括號里面的減法，然后根據(jù)除法的性質(zhì)計(jì)算即可．
④先算除法，再算加法；
⑤根據(jù)乘法分配律簡算即可．

解答 解：①19.5÷0.25÷0.4
=19.5÷（0.25×0.4）
=19.5÷0.1
=195
             
②0.36÷[（6.1-4.6）×0.8]
=0.36÷[1.5×0.8]
=0.36÷1.2
=0.3

③（45.9-32.7）÷8÷0.125         
=13.2÷（8×0.125）
=13.2÷1
=13.2

④59.5÷0.25+70
=238+70
=308

⑤6.73×5.8+0.42×67.3
=67.3×0.58+0.42×67.3
=67.3×（0.58+0.42）
=67.3×1
=67.3

點(diǎn)評 此題主要考查了小數(shù)四則混合運(yùn)算，注意運(yùn)算順序，注意乘法運(yùn)算定律以及除法的性質(zhì)的應(yīng)用．