999+99+9=?

999+99+9=? 9+99+999+9999+99999 = = 简算：9999+999+99+9=?） 9+99+999+9999+99999+999999=? 999+99+9+3=.简便计算 9+99+999+9999+9999+99999=? 简算要过程9216-999-99-9= 9+99+999=?怎么巧算? 999+99+9 (-9)+(-99)+(-999)+(-9999) 999×99×9巧算, 9999+999+99+9 (9+99+999+9999+99999+999999+9999999)×9×99×999×9999×99999÷9000000=? 9*99*999*9999*99999*999999=?3Q9*99*999*9999*99999*99999有规录 999×99=? 9999+999+99+9 = = 脱式计算要脱式计算要9999+999+99+9== 99999+9999+999+99+9=?请写出算式. 9+99+999+9999+99999= 简便方法