| 序号 | 题目：3,7,12,13 | |
|---|---|---|
| 1 | ((13 + 7) − 12) × 3 | |
| 2 | (13 − (12 − 7)) × 3 | |
| 3 | (7 + (13 − 12)) × 3 | |
| 4 | (13 + (12 ÷ 3)) + 7 | |
| 5 | (13 + 7) + (12 ÷ 3) | |
| 6 | (13 − 7) × (12 ÷ 3) | |
| 7 | (12 × (13 − 7)) ÷ 3 | |
| 8 | 12 × ((13 − 7) ÷ 3) | |
| 9 | 13 + (7 + (12 ÷ 3)) | |
| 10 | (13 − 7) ÷ (3 ÷ 12) | |
| 11 | 12 ÷ (3 ÷ (13 − 7)) | |