×0.87= | ÷1.2= | ÷ = | 0.56× = | 2006-619= |
6- = | 3.2× = | 0.3×0.4= | 2.85+1.5= | 73.05-3.96= |
= | = | = | 1÷ × = | 7× ÷7× = |
×0.87=0.09, | ÷1.2= , | ÷ =2, | 0.56× =0.07, | 2006-619=1387, |
6- =5 , | 3.2× =1, | 0.3×0.4=0.12, | 2.85+1.5=4.35, | 73.05-3.96=69.09, |
= , | = , | = , | 1÷ × = , | 7× ÷7× = . |
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;
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根据减法的性质简算;
,7×
÷7×
先把除法变成乘法,再运用乘法结合律简算;其它题目根据运算法则和运算顺序直接求解.
点评:口算题目要求快速准确,能运用简算方法的要简算.
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