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