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