+ = | ÷ = | 3-1.95= | × = | 6.3÷0.07= |
÷6= | 0÷ = | - = | +3÷ = | × -0.75× = |
解: + = , | ÷ = , | 3-1.95=1.05, | × = , | 6.3÷0.07=90, |
÷6= , | 0÷ =0, | - = , | +3÷ =12 , | × -0.75× =- . |
分析:同分母分数相加减,分母不变,分子相加减;异分母分数相加减,先通分,变成同分母的分数再相加减;
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;根据以上法则求解.
×
-0.75×
运用乘法分配律简算,注意运算的结果是负数.点评:本题考查了分数的计算,注意正确运用运算法则,把结果化成最简分数.
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