Roman numeral
From the Simple English Wikipedia, the free encyclopedia that anyone can change
A Roman numeral is the name for a number when it is written in the way the Romans used to write numbers. Roman numerals are not used very often today in the west. They are used to write the names of kings and queens, or popes. For example: Queen Elizabeth II. They may be used to write the year a book or film was made.
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[change] The base
I - 1
V - 5
X - 10
L - 50
C - 100
D - 500
M - 1000
If a lower value symbol is before a higher value one, it is subtracted. Otherwise it is added.
So 'IV' is '4' and 'VI' is '6'.
For the numbers above X, only the symbol right before it may be subtracted: so 99 is: XCIX (and not IC).
[change] Writing numbers
Numbers are written as Roman numerals in this way:
I = 1
II = 2
III = 3
IV = 4
V =5
VI = 6
VII = 7
VIII = 8
IX = 9
X = 10
XI = 11
XV = 15
XVI = 16
XIX = 19
XX = 20
XXX = 30
XL = 40
L = 50
LX = 60
LXI = 61
XC = 90
C = 100
CD = 400
D = 500
CM = 900
CMXC = 990
CMXCIX = 999
M = 1,000
MCMXCIX = 1,999
MM = 2,000
MMVII = 2007
MMVIII = 2008
[change] Notation
The System that is in use today is: Whenever the same symbol is written four times, it is replaced by subtracting it from the next higher number (5,50,500). That way, IV is written instead of IIII (4), XL instead of XXXX (40), etc.
Usually only one number is subtracted, not two. So 8 is always VIII and never IIX
Especially on clocks and watches, IIII can sometimes still be found. This is done partly because the IIII for the 4 o'clock position aesthetically balances the VIII for the 8 o'clock position.
Proper form is to subtract only a value with the next lower power of 10. Thus, 900 is written CM, but 990 would not be XM - properly, it is CM for the 900 portion and XC for the 90 portion, or CMXC. Similarly, 999 would not be IM but rather CMXCIX - CM for the 900 portion, XC for the 90 portion, and IX for the 9 portion. Only values with 1's are ever used to subtract; 45 is properly XLV, not VL.
Notations in Roman numerals for numbers higher than 3,000 are rarely seen. One system utilizes V and X with bars over them to signify 5,000 and 10,000, respectively.
[change] What they are used for
- In the Baltics and Russia, the days of the week, are often written as Roman numbers, I being Monday.
- When writing dates by hand, the month is sometimes written as a Roman numeral, especially for dates written in day-month-year sequence. Example: 26.XI.2007 = November 26, 2007.
- When films or books are published, the year of publication or year of copyright may be done as a Roman numeral.
- When people talk about Monarchs or Popes, Patriarchs, or other leading figures, they are sometimes counted with Roman numbers, eg. Queen Elizabeth II (of England), Pope John Paul II, Pope Benedict XVI, Patriarch Alexius II (of the Russian-Orthodox church)
- In France, the trimesters are sometimes counted with Roman numerals.