Identify the number before and after a given two-digit number
| 1. | 1 less, 1 more than 15 | |
| 2. | 1 less, 1 more than 17 | |
| 3. | 1 less, 1 more than 20 | |
| 4. | 1 less, 1 more than 8 | |
| 5. | 1 less, 1 more than 12 | |
| 6. | 1 less, 1 more than 37 | |
| 7. | 1 less, 1 more than 45 | |
| 8. | What Comes Next? - first even number after 13 | |
| 9. | What Comes Next? - first odd number after 13 | |
| 10. | What Comes Next? - first odd number after 12 |