Talen 84 till 90 i romerska siffror
I högerkolumnen visas hur varje romersk siffra bidrar till att man hamnar vid rätt tal.
| 84 | = | LXXXIV | = | 50 + 10 + 10 + 10 + 5 − 1 |
| 85 | = | LXXXV | = | 50 + 10 + 10 + 10 + 5 |
| 86 | = | LXXXVI | = | 50 + 10 + 10 + 10 + 5 + 1 |
| 87 | = | LXXXVII | = | 50 + 10 + 10 + 10 + 5 + 1 + 1 |
| 88 | = | LXXXVIII | = | 50 + 10 + 10 + 10 + 5 + 1 + 1 + 1 |
| 89 | = | LXXXIX | = | 50 + 10 + 10 + 10 + 10 − 1 |
| 90 | = | XC | = | 100 − 10 |