考點(diǎn):小數(shù)四則混合運(yùn)算,運(yùn)算定律與簡(jiǎn)便運(yùn)算
專(zhuān)題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:①③運(yùn)用一個(gè)數(shù)連續(xù)除以?xún)蓚€(gè)數(shù),可以用這個(gè)數(shù)除以這兩個(gè)數(shù)的積.
②運(yùn)用乘法的結(jié)合律及交換律進(jìn)行計(jì)算即可.
④⑤⑥按照四則混合運(yùn)算的順序進(jìn)行計(jì)算即可.
解答:
解:①9.8÷2.5÷0.4
=9.8÷(2.5×0.4)
=9.8÷1
=9.8;
②0.8×(0.175×1.25)
=(0.8×1.25)×0.175
=1×0.175
=0.175;
③16.8÷1.25÷0.8
=16.8÷(1.25×0.8)
=16.8÷1
=16.8;
④(34.28+45.43)÷0.5
=79.71÷0.5
=159.42;
⑤28.8×(4.8÷1.2)
=28.8×4
=115.2;
⑥116.9÷0.7-85.67
=167-85.67
=81.33.
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.