Talen 1820 till 1826 i romerska siffror
I högerkolumnen visas hur varje romersk siffra bidrar till att man hamnar vid rätt tal.
| 1820 | = | MDCCCXX | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 |
| 1821 | = | MDCCCXXI | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 1 |
| 1822 | = | MDCCCXXII | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 1 + 1 |
| 1823 | = | MDCCCXXIII | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 1 + 1 + 1 |
| 1824 | = | MDCCCXXIV | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 5 − 1 |
| 1825 | = | MDCCCXXV | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 5 |
| 1826 | = | MDCCCXXVI | = | 1000 + 500 + 100 + 100 + 100 + 10 + 10 + 5 + 1 |