计算:
(1)2-÷-+÷0.6×
(2)
(3)62.5%×(1+3)+
(4)51
网友回答
解:(1)2-÷-+÷0.6×,
=2-×-+××,
=2-,
=2-()+,
=2-2+,
=;
(2),
=[2+×-×]÷6,
=[+9-]÷6,
=×,
=1;
(3)62.5%×(1+3)+,
=62.5%×(1+3)+,
=×+×-,
=(-1)×,
=4×,
=;
(4)51,
=(50+)×+(70+)×+(90+)×,
=50××+70××+90××,
═30+1+40+1+50+1,
=123.
解析分析:(1)按照先算乘除,再算加减,有括号的先算括号里面的运算顺序计算;
(2)、(3)、(4)可以用乘法分配律简算.
点评:乘法分配律是常用的简便运算的方法,要熟练掌握,灵活运用.