0.56×40.5+0.44×59.5可不可以巧算

问题描述:

0.56×40.5+0.44×59.5可不可以巧算
第一位错了,答案与正确答案不符,正确答案是48.86

0.56×40.5+0.44×59.5
=0.56*40.5+0.44*(40*5+19)
=0.56*40.5+0.44*40.5+0.44*19
=40.5*(0.56+0.44)+8.36
=40.5+8.36
=48.86