9+99+999+9999+...99999999

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/12 04:35:54

9+99+999+9999...+99999999
=10+100+1000+10000+.+100000000-8
=111111110-8
=111111102

9+99+999+9999+99999+999999+9999999+99999999=? 9+99+999+9999+99999+999999+9999999+99999999+999999999+999999 9+99+999+9999+99999+999999+9999999+99999999=( ) 9+99+99+999+9999+99999+999999+999999+9999999+99999999+999999 9999999999＋999999999＋99999999＋99999＋9999＋999＋99＋9＝? 9999+999+99+9 9999+999+99+9+6 巧算 9+99+999+9999巧算简算9+99+999+9999 9+99+999+9999+9999+99999=? 9+99+999+9999+.+99999999=（10-1）+（10的平方-1）+.+（10的八次方-1）-8=?求后 9+99+999+9999+99999=? 99+9+999+9999+4简便计算