简便计算!0.1+0.2+0.3+0.4+0.+1.8+1.9
问题描述:
简便计算!0.1+0.2+0.3+0.4+0.+1.8+1.9
答
=(0.1+1.9)+(0.2+1.8)+...+(0.9+1.1)+1.0
=2*9+1
=19