题目内容
用简便方法计算.
(1)44.4×25
(2)0.64×125.
(1)44.4×25
(2)0.64×125.
分析:(1)把44.4看作40+4+0.4,运用乘法分配律简算;
(2)把0.64看作0.8×0.8,运用乘法分配律简算.
(2)把0.64看作0.8×0.8,运用乘法分配律简算.
解答:解:(1)44.4×25,
=(40+4+0.4)×25,
=40×25+4×25+0.4)×25,
=1000+100+10,
=1110;
(2)0.64×125,
=0.8×0.8×125,
=0.8×(0.8×125),
=0.8×100,
=80.
=(40+4+0.4)×25,
=40×25+4×25+0.4)×25,
=1000+100+10,
=1110;
(2)0.64×125,
=0.8×0.8×125,
=0.8×(0.8×125),
=0.8×100,
=80.
点评:此题主要通过数字拆分,运用乘法分配律进行简算.
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