题目内容
简便算法
17.08×2.53-7.08×2.53
100×0.97×99+3×99
19.25×9.5+19.25×0.4+0.1×19.25.
17.08×2.53-7.08×2.53
100×0.97×99+3×99
19.25×9.5+19.25×0.4+0.1×19.25.
分析:(1)运用乘法分配律简算;
(2)先算左边的第一个乘法,再运用乘法分配律简算;
(3)运用乘法分配律简算.
(2)先算左边的第一个乘法,再运用乘法分配律简算;
(3)运用乘法分配律简算.
解答:解:(1)17.08×2.53-7.08×2.53,
=(17.08-7.08)×2.53,
=10×2.53,
=25.3;
(2)100×0.97×99+3×99,
=97×99+3×99,
=(97+3)×99,
=100×99,
=9900;
(3)19.25×9.5+19.25×0.4+0.1×19.25,
=19.25×(9.5+0.4+0.1),
=19.5×10,
=195.
=(17.08-7.08)×2.53,
=10×2.53,
=25.3;
(2)100×0.97×99+3×99,
=97×99+3×99,
=(97+3)×99,
=100×99,
=9900;
(3)19.25×9.5+19.25×0.4+0.1×19.25,
=19.25×(9.5+0.4+0.1),
=19.5×10,
=195.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.
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