Good Math

9Roman Numerals

We normally write numbers in a notation that’s called arabic numbers, because it came to the European culture via Arabian mathematicians. But before that, in Western culture, numbers were written in the Roman style. In fact, in a lot of formal documents, we still use roman numerals. If you look at the preface to most textbooks, the pages are numbered with roman numerals. Every day on my way to work, I walk past buildings in Manhattan that have cornerstones recording the year the building was constructed, and every one uses roman numerals. In the closing titles of most movies, the copyright date is written in roman numerals.

Even though I’ve probably seen roman numerals every day of my life, I’ve always been perplexed by them. ...