Roman Numerals

Roman Numerals are numeric symbols, originally used by the Roman Empire, to show numeric values, such as LXII for 62, or MMXV for 2015. A Roman numeral can contain the following letters, to denote each value:

• I = 1
• V = 5
• X = 10
• L = 50
• C = 100
• D = 500
• M = 1000

Large Numbers

To write large numbers, like for instance five thousand, Romans would not use MMMMM. Rather, they would write V and put a horizontal bar "–" over the V. A bar over a letter represents one thousand times that letter.

Subtraction

Letters are put in order from greatest to least. A lesser letter occurring before a greater letter is subtraction. When subtracting, only subtracting a power of ten such as I, X, or C is allowed. For example, subtracting a V is not allowed, because VX could be more simply written as just V, and LC is the same as just L. Also, only one digit can be subtracted. For example, IIX is not 8 but rather use VIII for 8. Finally, one letter cannot be subtracted from another letter if it is ten times greater than it, so one would not be able to subtract X from M since M is one hundred times greater than X. Yet, X can be subtracted from either L or C, as XL (40) or XC (90). In Roman times, while any combination of numerals, which totals as the appropriate number, was considered sufficient, only the above method was considered proper. In rare cases, the number 9 is written as VIIII, rather than IX.

• Example 1983 = MCMLXXXIII
• Example 1200 = MCC
• Example 2011 = MMXI

Modern Use

While the system of Arabic numerals has become the standard contemporary numeral system, Roman numerals are still used today in limited settings. They express years on building cornerstones or denote an epoch which dates art or literature. They also count installments in a series, such as movie sequel numbers, each Super Bowl, or each Olympiad of the Olympics. Roman numerals also designate the ordering of monarchs (i.e., Queen Elizabeth II or France's King Louis XIV).

Usage

• I - 1
• II - 2
• III - 3
• IV - 4
• V - 5
• VI - 6
• VII - 7
• VIII - 8
• IX - 9
• X - 10
• XI - 11
• XII - 12