口算
(1)12÷ = | (2)1÷1%= | (3)9.5+0.5= | (4) + = | (5)0÷ ×2= |
(6)1- = | (7) × = | (8) ÷ = | (9) - = | (10) × ×9= |
(1)12÷ =24, | (2)1÷1%=100, | (3)9.5+0.5=10, | (4) + = , | (5)0÷ ×2=0, |
(6)1- = , | (7) × = , | (8) ÷ = , | (9) - = , | (10) × ×9= . |
分析:分数乘法:分子相乘的积做分子,分母相乘的积做分母;
分数除法:除以一个数等于乘这个数的倒数;
异分母分数相加减,分母不变,分子相加减.
(10)运用乘法交换律简算.
点评:本题考查了简单分数的计算,注意把结果化成最简分数.
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