题目内容
能简算的要简算
0.125×0.25×32=________;
3.25×25+32.5×7.5=________;
4.06×76+4.06×25-4.06=________;
0.125×+×8.25+12.5%=________.
1 325 406 1.25
分析:(1)把32看作4×8,运用乘法交换律与结合律简算;
(2)根据数字特点,把原式变为3.25×25+3.25×75,运用乘法分配律简算;
(3)运用乘法分配律简算;
(4)把分数和百分数化为小数,运用乘法分配律简算.
解答:(1)0.125×0.25×32,
=0.125×0.25×4×8,
=(0.125×8)×(0.25×4),
=1×1,
=1;
(2)3.25×25+32.5×7.5,
=3.25×25+3.25×75,
=3.25×(25+75),
=3.25×100,
=325;
(3)4.06×76+4.06×25-4.06,
=4.06×(76+25-1),
=4.06×100,
=406;
(4)0.125×+×8.25+12.5%,
=0.125×0.75+0.125×8.25+0.125,
=0.125×(0.75+8.25+1),
=0.125×10,
=1.25.
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.
分析:(1)把32看作4×8,运用乘法交换律与结合律简算;
(2)根据数字特点,把原式变为3.25×25+3.25×75,运用乘法分配律简算;
(3)运用乘法分配律简算;
(4)把分数和百分数化为小数,运用乘法分配律简算.
解答:(1)0.125×0.25×32,
=0.125×0.25×4×8,
=(0.125×8)×(0.25×4),
=1×1,
=1;
(2)3.25×25+32.5×7.5,
=3.25×25+3.25×75,
=3.25×(25+75),
=3.25×100,
=325;
(3)4.06×76+4.06×25-4.06,
=4.06×(76+25-1),
=4.06×100,
=406;
(4)0.125×+×8.25+12.5%,
=0.125×0.75+0.125×8.25+0.125,
=0.125×(0.75+8.25+1),
=0.125×10,
=1.25.
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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