55x55/56=?的简便算法?
问题描述：
55x55/56=?的简便算法?
答
=(55*55-1+1)/56
=(55+1)(55-1)/56 + 1/56
=54又56分之1
答
55×55/56
＝（56－1）×55/56
＝56×55/56－1×55/56
＝55－55/56
＝54又1/56