Roman numerals are a number system invented by the ancient Romans over 2,000 years ago, using letters instead of the digits we normally use today. In this system, I means 1, V means 5, X means 10, L means 50, C means 100, D means 500, and M means 1,000.

You combine these letters to make other numbers. Put a smaller value before a larger one and you subtract: IV means 4 (one before five), IX means 9 (one before ten). Put letters in descending order and you add: VI means 6 (five plus one), XI means 11 (ten plus one). The year 2024 becomes MMXXIV: two thousands (MM), two tens (XX), and four (IV).

You'll spot Roman numerals on clock faces, in book chapters, after names of kings and queens (Queen Elizabeth II), at the end of movies showing the copyright year, and on building cornerstones. They're not practical for complex math, which is why we use Arabic numerals (0–9) for everyday calculations. But Roman numerals carry a sense of tradition, formality, and importance. That's why the Super Bowl uses them: Super Bowl LIX sounds more dignified than Super Bowl 59.