Talen 1637 till 1643 i romerska siffror
I högerkolumnen visas hur varje romersk siffra bidrar till att man hamnar vid rätt tal.
| 1637 | = | MDCXXXVII | = | 1000 + 500 + 100 + 10 + 10 + 10 + 5 + 1 + 1 |
| 1638 | = | MDCXXXVIII | = | 1000 + 500 + 100 + 10 + 10 + 10 + 5 + 1 + 1 + 1 |
| 1639 | = | MDCXXXIX | = | 1000 + 500 + 100 + 10 + 10 + 10 + 10 − 1 |
| 1640 | = | MDCXL | = | 1000 + 500 + 100 + 50 − 10 |
| 1641 | = | MDCXLI | = | 1000 + 500 + 100 + 50 − 10 + 1 |
| 1642 | = | MDCXLII | = | 1000 + 500 + 100 + 50 − 10 + 1 + 1 |
| 1643 | = | MDCXLIII | = | 1000 + 500 + 100 + 50 − 10 + 1 + 1 + 1 |