99+99乘99+999乘999乘999的巧算
问题描述：
99+99乘99+999乘999乘999的巧算
3分钟
答
=99*(99+1)+999*(1000*999-1*999) =99*100+999*(999000-999) =9900+999*998001 =9900+(1000-1)*998001 =9900+1000*998001-998001 =9900+(998001000-998001) =9900+997002999 =997012899