Roman numerals from 1 to 100

Roman numerals use seven letters: I (1), V (5), X (10), L (50), C (100), D (500) and M (1000). A symbol before a larger one subtracts (IV = 4, IX = 9, XL = 40, XC = 90) and after it adds (VI = 6, XI = 11). No symbol repeats more than three times in a row. Here is the full chart from 1 to 100 and a converter for any number up to 3999.