Roman numerals pertain to any of the symbols used in the Roman numeral system comprising the letters I, V, X, L, C, D and M, with corresponding values of 1, 5, 10, 50, 100, 500 and 1,000, respectively. These base letters are used in combination with each other in writing down numbers. Basic combinations follow certain rules in the additive and subtractive system of Roman numerals.
The modern version of the Roman number system developed in Western Europe during the Middle Ages. It was derived and built upon from an earlier form used by the Ancient Roman Empire. Although the use of Roman numerals in mathematical computations has been outdated, this numeral system still remains popular in some areas. Roman numerals are commonly used in designing clocks, paging the introductory parts of a book, enumerating items in a list and denoting copyright dates.
Roman Numerals were not only used for counting the number of objects but also the order of people sharing the same name. For example, Pope Benedict XV was the 15th pope, and Pope Benedict XVI was the 16th pope.
Certain rules apply in manipulating the base Roman numerals to form numbers. As a general additive rule, when used in combinations, a larger unit is always placed before a smaller unit. The Roman number XX is the same as 10 + 10, which is equal to 20. In case of a smaller unit preceding a larger unit, the smaller unit is subtracted from the larger unit to get the value. The Roman number IV is the same as 5 - 1, which is equivalent to 4. Romans numbers with a bar on top are to be multiplied by 1,000.
One of the main problems with the Roman numeral system is that it does not contain a symbol for the number zero, which is one of the reasons it fell out of use.