| 计算:9992+999+10012-1001 |
答案:
| 9992+999+10012-1001=999(999+1)+1001(1001-1) =999×1000+1001×1000 =(999+1001)×1000 =2000×1000=2000000. |

| 计算:9992+999+10012-1001 |
答案:
| 9992+999+10012-1001=999(999+1)+1001(1001-1) =999×1000+1001×1000 =(999+1001)×1000 =2000×1000=2000000. |