There are a total of zero zeros in Roman numerals. While the ancient Greeks were aware of zero as a concept, they didn't consider zero to be a number at all. For example, Aristotle decided zero wasn't a number because you couldn't divide by zero. Instead of a Roman numeral, the Latin word "nulla" would have been used to represent the concept of zero. The reason no numeral existed for zero is because there was no need for a numeral to represent it.