You'll find many writers use Roman Numerals in their Bible references. Below is a brief tool to help you determine the numeric values we use today. This is not meant to be an all-inclusive list so you may have to "calculate" the equivelant of a Roman number.

Roman Numerals use a base numbering system with letters. Base numbers include:

c	100
i	1
l	50
v	5
x	10

And are combined to make other numbers. Examples are:
xviii = 18 (10+5+3)
lxxviii = 78 (50+10+10+5+3)
cxix = 119 (100 + 10 + 9)

Combining a letter before another reduces the second number's value (confusing, isn't it):
"i" before letter = - (minus) one. Ie, ix = 9 and iv = 4
"x" before "l" (xl) = 40

Examples of combined letters:

ciii	103
cxix	119
ii	2
iii	3
iv	4
ix	9
lxxvii	78
vi	6
vii	7
xc	90
xlv	45
xvii	17
xxv	25
xxvii	27