Why Roman numerals don't have number zero.
Answers
Roman number system does not contain the number zero.
The roman number system was basically designed to estimate the prices of goods and trading business.
So the roman system did not need any value to represent zero.
But instead of zero, the word nulla was used by the Romans to specify zero.
I Latin language the word nulla means none.
Hence nulla is used t represent zero but there is no specific symbol for zero to represent in roman number system.
Before I answer your question, let’s focus on the discovery of the most beautiful concept of mathematics, Zero '0′.
It's hard to say when and where "zero" originated.
Some says the Indian mathematician Brahmagupta was the earliest to introduce formal concept of zero in number system.
Some says Aryabhatta (476-550 AD) an Indian mathematician invented zero as a digit.
But the truth is, Zero was invented independently by the Babylonians, Mayans and Indians (although some researchers say the Indian number system was influenced by the Babylonians). The Babylonians got their number system from the Sumerians, the first people in the world to develop a counting system. Mayans and the Mexicans were the first to use the concept of zero and that is why they developed their number system so early and made their calendars which are still known as the earliest calendars up till now.
THE ancient Greeks were aware of the concept of zero (as in 'We have no marbles'), but didn't think of it as a number. Aristotle had dismissed it because you couldn't divide by zero. The Romans never used their numerals for arithmetic, thus avoiding the need to keep a column empty with a zero symbol. Addition and subtraction were done instead on an abacus. About 1,500 years ago, a symbol was used to represent an abacus column with nothing in it. At first this was just a dot; later it became the '0' we know today. In the 8th century the great Arab mathematician, took it up and the Arabs eventually brought the zero to Europe. It wasn't warmly received; the Italians in particular were very suspicious of any change to their ancestors' system of numerals. In 1259 a law was passed forbidding bankers from using zero or any of the new Arab numerals in their accounts.
Even in the earliest examples, there were numeral systems (Arabic for example) that used some form of zero, but only as a placeholder. Roman numerals actually originated before zero was ever used anywhere, even as a placeholder (as far as we can tell), and the western world picked up on that practice pretty late. By the time Fibonacci brought that concept to the west, in the 13th century, other parts of the world had already been using zero for hundreds of years. Romans never welcomed this concept of zero.
What I believe is, Romans were people who have huge egos! and that is the reason behind their non-acceptance of the concept of zero.
I hope it helps! :-)