题目内容
简便运算
①6.2×10.1
②1.25×32×0.25
③35.4×44.2-35.3×44.3.
解:①6.2×10.1,
=6.2×(10+0.1),
=62+0.62,
=62.62;
②1.25×32×0.25,
=1.25×8×4×0.25,
=(1.25×8)×(4×0.25),
=10×1,
=10;
③35.4×44.2-35.3×44.3,
=(35.4-35.3)×44.3,
=0.1×44.3,
=4.43.
分析:①把10.1看作10+0.1,运用乘法分配律简算;
②把32看作8×4,运用乘法结合律简算;
③运用乘法分配律简算.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
=6.2×(10+0.1),
=62+0.62,
=62.62;
②1.25×32×0.25,
=1.25×8×4×0.25,
=(1.25×8)×(4×0.25),
=10×1,
=10;
③35.4×44.2-35.3×44.3,
=(35.4-35.3)×44.3,
=0.1×44.3,
=4.43.
分析:①把10.1看作10+0.1,运用乘法分配律简算;
②把32看作8×4,运用乘法结合律简算;
③运用乘法分配律简算.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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