| 年级 | 科目 | 问题描述 | 提问时间 |
| 三年级 | 数学 | jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj | 2014-08-11 10:39:15 |
简便计算 (9+99+999)*9999 = | |||
| 钟凯鑫 2014-08-11 11:30:53 | |||
（9+99+999）*9999 =(9+99+999）*10000-9-99-999 =11068893 | |||
| 学点点闵老师 2014-08-11 11:11:29 | |||
（10-1+100-1+1000-1）*9999 =（1110-3）*（10000-1） =1107*10000-1107 =11070000-1107 =11068893 | |||
