2+1.9-1.8+1.7-1.6+.+0.3-0.2+0.1

问题描述:

2+1.9-1.8+1.7-1.6+.+0.3-0.2+0.1

2+1.9-1.8+1.7-1.6+.+0.3-0.2+0.1=2+(1.9-1.8)+(1.7-1.6)+……+(0.3-0.2)+0.1 =2+0.1+0.1+……+0.1+0.1 =2+0.1×9+0.1 =2+1=3 答:值是3.