Over a whole number it was to ensure that it was understood as a number and not a word (also often underlined as well so the number appears between two lines);
Otherwise multiply it by 1000, for example:
_
V = 5 x 1,000 = 5,000
It indicates multiplication by a thousand
A bar or a line over a particular Roman numeral indicates that it is to be multiplied by a thousand.
This is not a valid roman numeral!
It is: 5 = V as a Roman numeral
The Roman numeral of DXIII is equivalent to 513
It indicates multiplication by a thousand
In todays modern usage of Roman numerals it indicates multiplication by a thousand.
A bar or a line over a particular Roman numeral indicates that it is to be multiplied by a thousand.
This is not a valid roman numeral!
It is: 5 = V as a Roman numeral
LXXVI is the Roman numeral for 76.
The Roman numeral of DXIII is equivalent to 513
You mean Roman Numeral? It is XVI
The roman numeral M represents the number 1000.
The Roman numeral CCLXVI represents the number 266
The Roman numeral CXXXVI represents the number 136
The Roman numeral MCMXC represents the number 1990