ROMAN NUMERALS
Our numbers (0-9) are called Arabic numerals because they originated in Arabic. Roman numerals are used in certain circumstances, including representing oxidation states of atoms when placed in brackets after the name of the atom, for example chromium(III). For cleverer information on how to use Roman numerals, go to Math Forum. Rule Any smaller number placed before a larger number means the smaller number is to be subtracted from the larger number. For example, I = 1, X = 10. IX = 10 - 1 = 9.
ROMAN NUMERAL	NUMBER IT REPRESENTS
I	1
II	2
III	3
IV	4
V	5
VI	6
VII	7
VIII	8
IX	9
X	10
XI	11
XII	12
XIII	13
XIV	14
XV	15
XVI	16
XVII	17
XVIII	18
XIX	19
XX	20
I	1
V	5
X	10
L	50
C	100
D	500
M	1000
CM	900
MCM	1900
MCMXXXIX	1939
MCMXL	1940
MCML	1950
MCMLXXXV	1985
MCMXCVII	1997
MCMXCIX	1999
MM	2000
MMI	2001
MMII	2002
MMIII	2003
MMIV	2004
MMV	2005
MMM	3000