9.9+99.9+999.9+9999.9求巧算

问题描述:

9.9+99.9+999.9+9999.9求巧算

9.9+99.9+999.9+9999.9
=(10-0.1)+(100-0.1)+(1000-0.1)+(10000-0.1)
=11110-0.4
=11109.6