计算(能简算的要简算)
1.2×5.5-0.45×12????????????????????
×+÷+
12÷(+)????????????????????
(+×+)÷.
网友回答
解:(1)1.2×5.5-0.45×12,
=1.2×5.5-4.5×1.2,
=(5.5-4.5)×1.2,
=1×1.2,
=1.2;
(2)×+÷+,
=×+×+,
=(++1)×,
=2×,
=;
(3)12÷(+),
=12÷,
=12×,
=;
(4)(+×+)÷,
=(++)÷,
=[+(+)]÷,
=[+1]÷,
=×,
=.
解析分析:(1)根据数字特点,把原式变为1.2×5.5-4.5×1.2,运用乘法分配律的逆运算简算;(2)把除法改为乘法,运用乘法分配律的逆运算简算;(3)先算括号内的,再算括号外的;(4)先算括号内的乘法,原式变为(++)÷,括号内运用加法结合律简算,最后除以.
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.