口算下面各题.
(1) ÷ = | (2)0÷ = | (3)1÷ = | (4) ÷1= | (5)![]() = |
(6) ÷3= | (7) × = | (8) = | (9) = | (10) . |
(1) ÷ =1, | (2)0÷ =0, | (3)1÷ = , | (4) ÷1= , | (5)![]() =2, |
(6) ÷3= , | (7) × = , | (8) = , | (9) =2, | (10) = . |
分析:分数除法的计算方法:除以一个不等于0的数,等于乘这个数的倒数,进而把分母和分母相乘的积做分母,分子和分子相乘的积做分子,能约分的要先约分再计算.
点评:本题考查基本的分数除法的计算,要注意在计算分数除法时,有两变:除号变乘号,除数变倒数;还要注意结果要化成最简分数.
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