| 序号 | 题目：1,3,3,9 | |
|---|---|---|
| 1 | ((9 × 3) − 3) × 1 | |
| 2 | ((9 × 1) × 3) − 3 | |
| 3 | ((9 × 3) × 1) − 3 | |
| 4 | (9 − 3) × (3 + 1) | |
| 5 | (9 × 3) − (3 × 1) | |
| 6 | (9 × (3 × 1)) − 3 | |
| 7 | (9 + 3) × (3 − 1) | |
| 8 | ((9 × 3) ÷ 1) − 3 | |
| 9 | ((9 × 3) − 3) ÷ 1 | |
| 10 | ((9 ÷ 1) × 3) − 3 | |
| 11 | (9 × 3) − (3 ÷ 1) | |
| 12 | (9 × (3 ÷ 1)) − 3 | |
| 13 | (9 ÷ (1 ÷ 3)) − 3 | |
| 14 | (3 ÷ (1 ÷ 9)) − 3 | |
| 15 | 9 × (3 − (1 ÷ 3)) | |