脱式计算,能简算的要简算:
46.5×99+46.5?????????????4.85×1.25×8(455-12.5×4)÷8.1??????????(0.5+0.25)×439÷0.125÷0.8.
网友回答
解:(1)46.5×99+46.5,
=46.5×(99+1),
=46.5×100,
=4650;
(2)4.85×1.25×8,
=4.85×(1.25×8),
=4.85×10,
=48.5;
(3)(455-12.5×4)÷8.1,
=(455-50)÷8.1,
=405÷8.1,
=50;
(4)(0.5+0.25)×4,
=0.5×4+0.25×4,
=2+1,
=3;
(5)39÷0.125÷0.8,
=39÷(0.125×0.8),
=39÷0.1,
=390.
解析分析:(1)运用乘法分配律解答,(2)运用乘法结合律解答,(3)依据四则运算计算方法:先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的解答,(4)运用乘法分配律解答,(5)依据除法的性质解答.
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.