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