The numbers 18 to 24 in roman numerals
The right column shows how each roman numeral adds up to the total.
| 18 | = | XVIII | = | 10 + 5 + 1 + 1 + 1 |
| 19 | = | XIX | = | 10 + 10 − 1 |
| 20 | = | XX | = | 10 + 10 |
| 21 | = | XXI | = | 10 + 10 + 1 |
| 22 | = | XXII | = | 10 + 10 + 1 + 1 |
| 23 | = | XXIII | = | 10 + 10 + 1 + 1 + 1 |
| 24 | = | XXIV | = | 10 + 10 + 5 − 1 |