(2.5÷2+2÷2.5)×0.4怎么巧算,简单,准确的

2024-11-26 05:41:31
推荐回答(3个)
回答1:

原式
=2.5÷2x0.4+2÷2.5x0.4
=1÷2+0.8÷2.5
=0.5+0.32
=0.82

回答2:

化成分数算。
(2.5÷2+2÷2.5)×0.4
=[(5/2)x(1/2)+2x(2/5)]x2/5
=(1/2)+(8/25)
=(25/50+(16/50)
=41/50
=0.82.

回答3:

(2.5÷2+2÷2.5)×0.4
=2.5×0.4÷2+2×0.4÷2.5
=1÷2+0.8÷2.5
=0.5+0.32
=0.82