Here are the Roman numerals and their corresponding value: I(1), V(5), X(10), L(50), C(100), D(500), M(1000).
Below are some of the examples:
| Roman numeral string | Explain | Decimal Value |
|---|
| II | 1+1 | 2 |
| III | 1+1+1 | 3 |
| IV | (5-1) | 4 |
| VI | 5+1 | 6 |
| VII | 5+1+1 | 7 |
| VIII | 5+1+1+1 | 8 |
| IX | (10-1) | 9 |
| XI | 10+1 | 11 |
| XXI | 10+10+1 | 21 |
| XXXIX | 10+10+10+(10-1) | 39 |
| XLII | (50-10)+1+1 | 42 |
| LVIII | 50+5+1+1+1 | 58 |
Note that when a smaller Roman numeral is on the left of another Roman numeral that is larger in value, the smaller Roman numeral value needs to be subtracted from the sum.