零点二五乘九点八成是姐妹计算乘法方法怎样算
问题描述：
零点二五乘九点八成是姐妹计算乘法方法怎样算
答
0.25×9.8=0.25×(10-0.2)
=0.25×10+0.25×0.2
=2.5+0.05
=2.55