简便方法计算.3 1 2 ÷4+360×25%+0.25×36.5;(7.25×40%+2.75× 2 5 )÷20%;[1.9+19%×(4.8-3 4 5 )]÷(2 9 10 -190%)
(1)3
=3.5×
=3.5×0.25+360×0.25+0.25×36.5 =(3.5+36.5+360)×0.25 =400×0.25 =100; (2)(7.25×40%+2.75×
=(7.25×40%+2.75×40%)÷20% =(7.25+2.75)×40%÷20% =10×40%÷20% =4÷20% =20; (3)[1.9+19%×(4.8-3
=[1.9+0.19×(4.8-3.8)]÷(2.9-1.9) =(1.9+0.19×1)÷1 =(1.9+0.19)÷1 =2.09÷1 =2.09. |