能简算的要简算.
(-)×15
40%×+÷39××0.125×+÷+12.5%×.
网友回答
解:(1)(-)×15,
=×15-×15,
=12-10,
=2;
(2)40%×+÷,
=×+×,
=×(+),
=×1,
=;
(3)39××,
=(39×)×,
=21×,
=;
(4)0.125×+÷+12.5%×,
=0.125×+0.125×+0.125×,
=0.125×(++),
=0.125×1,
=0.125.
解析分析:(1)运用乘法分配律简算;(2)把40%化成分数,把除法变为乘法,运用乘法分配律简算;(3)运用乘法交换律与结合律简算;(4)把和12.5%化为小数0.125,运用乘法分配律简算.
点评:考查了四则混合运算,注意数字转化,灵活运用所学的运算定律简便计算.