题目内容
脱式计算,能简便的要用简便方法计算. 0.36×1.5×0.4 |
0.05×3.2×40 | 26×15.7+15.7×74 |
3.78×0.5-0.65 | 3.98+13.4×0.24 | (9.37+9.37+9.37+9.37)×2.5. |
分析:(1)、(2)用乘法结合律简算;
(3)用乘法分配律简算;
(4)、(5)按照先算乘法,再算加减的运算顺序计算;
(6)先根据乘法的意义改写成3个数相乘的形式,再运用乘法结合律简算.
(3)用乘法分配律简算;
(4)、(5)按照先算乘法,再算加减的运算顺序计算;
(6)先根据乘法的意义改写成3个数相乘的形式,再运用乘法结合律简算.
解答:解:(1)0.36×1.5×0.4,
=0.36×(1.5×0.4),
=0.36×0.6,
=0.216;
(2)0.05×3.2×40,
=(0.05×40)×3.2,
=2×3.2
=6.4;
(3)26×15.7+15.7×74,
=(26+74)×15.7,
=100×15.7,
=1570;
(4)3.78×0.5-0.65,
=1.89-0.65,
=1.24;
(5)3.98+13.4×0.24,
=3.98+3.216,
=7.196;
(6)(9.37+9.37+9.37+9.37)×2.5,
=9.37×4×2.5,
=9.37×(4×2.5),
=9.37×10,
=93.7.
=0.36×(1.5×0.4),
=0.36×0.6,
=0.216;
(2)0.05×3.2×40,
=(0.05×40)×3.2,
=2×3.2
=6.4;
(3)26×15.7+15.7×74,
=(26+74)×15.7,
=100×15.7,
=1570;
(4)3.78×0.5-0.65,
=1.89-0.65,
=1.24;
(5)3.98+13.4×0.24,
=3.98+3.216,
=7.196;
(6)(9.37+9.37+9.37+9.37)×2.5,
=9.37×4×2.5,
=9.37×(4×2.5),
=9.37×10,
=93.7.
点评:运算定律是常用的简便运算的方法,要熟练掌握,灵活运用.
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