### Roman Numerals

Roman Numerals are a number used by the European before the introduction of the Arabic numerals and are now less applied. However, its production marks the progress of an ancient civilization.

Roman Numerals are not a positional system and contain no symbol of zero. Rather, they are an additive system with each symbol taking on a definite numeric value regardless of where it appears. Actually there a few subtractive rules that makes writing a value somewhat more compact that do depend upon position relative to another symbol.

In this system of numbering seven symbols are used which are letters of the alphabet.

The symbols and their values are:

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

The numbers were divided into Primary and Secondary.

a) Primary numbers: are those that can be repeated up to three times in a row.

I = 1 C = 100

X = 10 M = 1,000

b) Secondary numbers: are those that can not be repeated.

V = 5 L = 50 D = 500

The table can be extended to larger values by using the convention that a bar over a symbol indicates "1000 times:"

 V X L C D M 5000 10,000 50,000 100,000 500,000 1,000,000

To write the Roman numerals, three fundamental principles must be considered:

a) Principle or additive: a symbol of lower value located to the right of another one of greater value, its value is added to it.

CXII = 100 + 10 + 2 = 112

b) Subtraction principle: a symbol of lower value located to the left of a higher value, is subtracted from this value.

CM = 1,000 - 100 = 900

c) Principle multiplicative: to express larger quantities draw a line on the symbols, indicating that it should be multiplied by 5000.

## Common use

1. They are still used in almost all cases for the copyright date on films, television programmes, and videos.
2. Element Periodic Table: Group IA, Group IIA, Group IIIA, Group IVA, Group V, Group VIA, Group VIIA, Group IB, Group IIIB, Group IIIB, IVB, VB, VIB, VIIB and VIII.
3. They are also used to show the hours on some analogue clocks and watches.
4. They can be used for the preliminary pages of book before the main page numbering gets under way. Here they numerals normally use lower case letters so pages i, iv, xi and so on.
5. They are also used in names of monarchs, popes, ships and sporting events, like the Olympics and the Super Bowl.
6. They are found in numbering paragraphs in complex documents to clarify which are main sections and which subsections so II.3.iv.(5). And they are used for similar reasons to show the volume number of periodicals eg vol.VI no.5