0.9 1.9 19.9 199.9用简算怎么算?
问题描述：
0.9 1.9 19.9 199.9用简算怎么算?
答
(0.9+0.1)+(1.9+0.1)+(19.9+0.1)+(199.9+0.1)-4*0.1=222.6
0.9 1.9 19.9 199.9用简算怎么算?
(0.9+0.1)+(1.9+0.1)+(19.9+0.1)+(199.9+0.1)-4*0.1=222.6