直接写得数 + = | + = | 1- = | + = | + = |
- = | + + = | 9.2×0.25×4= | 0.8×25-10= | 5÷8= |
+ = , | + = , | 1- = , | + = , | + = , |
- =0, | + + =1 , | 9.2×0.25×4=9.2, | 0.8×25-10=10, | 5÷8= . |
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,化成同分母的分数,再计算;
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运用加法交换律简算;9.2×0.25×4运用乘法结合律简算;0.8×25-10先算乘法,再算减法.点评:本题主要考查了分数的加减法,注意运算法则和运算定律,把结果化成最简分数.
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