题目内容
计算下列各题,能简算的用简便方法计算. 26-3.17-7.83 | 67×38+33×38 | 125×25×64 |
29.38-(19.38-4.76) | 329×87-87×29 | 5.8-3.62-0.38+0.2. |
解:(1)26-3.17-7.83,
=26-(3.17+7.83),
=26-11,
=15;
(2)67×38+33×38,
=(67+33)×38,
=100×38,
=3800;
(3)125×25×64,
=125×25×4×8,
=(125×8)×(25×4),
=1000×100,
=100000;
(4)29.38-(19.38-4.76),
=29.38-19.38+4.76,
=10+4.76,
=14.76;
(5)329×87-87×29,
=(329-29)×87,
=300×87,
=26100;
(6)5.8-3.62-0.38+0.2,
=(5.8+0.2)-(3.62+0.38),
=6-4,
=2.
分析:(1)(4)运用减法的性质简算;
(2)(5)运用乘法分配律简算;
(3)把64看作4×8,运用乘法交换律与结合律简算;
(6)运用加法交换律与结合律简算.
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.
=26-(3.17+7.83),
=26-11,
=15;
(2)67×38+33×38,
=(67+33)×38,
=100×38,
=3800;
(3)125×25×64,
=125×25×4×8,
=(125×8)×(25×4),
=1000×100,
=100000;
(4)29.38-(19.38-4.76),
=29.38-19.38+4.76,
=10+4.76,
=14.76;
(5)329×87-87×29,
=(329-29)×87,
=300×87,
=26100;
(6)5.8-3.62-0.38+0.2,
=(5.8+0.2)-(3.62+0.38),
=6-4,
=2.
分析:(1)(4)运用减法的性质简算;
(2)(5)运用乘法分配律简算;
(3)把64看作4×8,运用乘法交换律与结合律简算;
(6)运用加法交换律与结合律简算.
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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