题目内容
用简便方法计算.
8.37×7.2+8.37×2.8
12.5×3.9×0.8
1.3+2.9+8.7+0.1
9.6×10.1.
解:
(1)8.37×7.2+8.37×2.8,
=8.37×(7.2+2.8),
=8.37×10,
=83.7;
(2)12.5×3.9×0.8,
=12.5×0.8×3.9,
=10×3.9,
=39;
(3)1.3+2.9+8.7+0.1,
=(1.3+8.7)+(2.9+0.1),
=10+3,
=13;
(4)9.6×10.1,
=9.6×(10+0.1),
=9.6×10+9.6×0.1,
=96×0.96,
=96.96.
分析:(1)根据乘法分配律进行计算;
(2)根据乘法交换律进行计算;
(3)根据加法交换律和结合律进行计算;
(4)根据乘法分配律进行计算.
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.
(1)8.37×7.2+8.37×2.8,
=8.37×(7.2+2.8),
=8.37×10,
=83.7;
(2)12.5×3.9×0.8,
=12.5×0.8×3.9,
=10×3.9,
=39;
(3)1.3+2.9+8.7+0.1,
=(1.3+8.7)+(2.9+0.1),
=10+3,
=13;
(4)9.6×10.1,
=9.6×(10+0.1),
=9.6×10+9.6×0.1,
=96×0.96,
=96.96.
分析:(1)根据乘法分配律进行计算;
(2)根据乘法交换律进行计算;
(3)根据加法交换律和结合律进行计算;
(4)根据乘法分配律进行计算.
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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