Definition: Roman numerals from Dictionary of Computing

numbers represented using the symbols I, V, X, L, C, D and M

Summary Article: Roman numerals
from The Hutchinson Unabridged Encyclopedia with Atlas and Weather Guide

Ancient European number system using symbols different from Arabic numerals (the ordinary numbers 1, 2, 3, 4, 5, and so on). The seven key symbols in Roman numerals, as represented today, are I (1), V (5), X (10), L (50), C (100), D (500), and M (1,000). There is no zero, and therefore no place-value as is fundamental to the Arabic system. The first ten Roman numerals are I, II, III, IV (or IIII), V, VI, VII, VIII, IX, and X. When a Roman symbol is preceded by a symbol of equal or greater value, the values of the symbols are added (XVI = 16).

When a symbol is preceded by a symbol of less value, the values are subtracted (XL = 40). A horizontal bar over a symbol indicates a multiple of 1,000 (X̄ = 10,000). Although addition and subtraction are fairly straightforward using Roman numerals, the absence of a zero makes other arithmetic calculations (such as multiplication) clumsy and difficult.

memjoggers

Roman numerals: order

Roman numerals: values

### Related Articles

##### Full text Article Roman numerals
The Macmillan Encyclopedia

The system of numbers used by the Romans, based on letters of the alphabet: I=1, V=5, X=10, L=50, C=100, D=500, and M=1000. Intermediate...

##### Full text Article Roman numerals
The Thames & Hudson Dictionary of Graphic Design and Designers

Numerical notation system developed by the Romans. Based on a combination of symbols and capital letters, the system was subsequently replaced by the

##### Full text Article Roman numerals
Dictionary of Publishing and Printing

/remən njuəmərəlz/ , Roman figures noun figures written I, II, III, IV, or i, ii, iii, iv, etc. (as opposed to Arabic numerals such as 1,...

See more from Credo