简便计算. 8.2×99+8.28.8×12.50.78×9.912.5×3.4×0.84.5×13.6+55×1.36.
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解:(1)8.2×99+8.2,
=8.2×(99+1),
=8.2×100,
=820;
(2)8.8×12.5,
=(8+0.8)×12.5,
=100+10,
=110;
(3)0.78×9.9,
=0.78×(10-0.1),
=0.78×10-0.78×0.1,
=7.8-0.078,
=7.722;
(4)12.5×3.4×0.8,
=12.5×0.8×3.4,
=10×3.4,
=34;
(5)4.5×13.6+55×1.36,
=45×1.36+55×1.36,
=(45+55)×1.36,
=100×1.36,
=136.
解析分析:(1)运用乘法分配律简算;(2)把8.8看作8+0.8,运用乘法分配律简算;(3)把9.9看作10-0.1,运用乘法分配律简算;(4)运用乘法交换律简算;(5)先把原式变为45×1.36+55×1.36,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.