I = 1 V = 5 X = 10 L = 50 C = 100 D = 500 M = 1000
I Value Xylophones Like Cows Do Milk.
VI = 5 + 1 = 6 LXI = 50 + 10 + 1 = 61 III = 1 + 1 + 1 = 3
IV = 1 subtracted from 5 = 5 - 1 = 4 IX = 1 subtracted from 10 = 10 - 1 = 9 XL = 10 subtracted from 50 = 50 - 10 = 40 XC = 10 subtracted from 100 = 100 - 10 = 90 CM = 100 subtracted from 1000 = 1000 - 100 = 900
For example, try to read DCCXCIX. There are two places in the number with a small digit in front of a larger one: XC and IX. Keep the “subtraction problems” together and break up the other digits separately: D + C + C + XC + IX. Translate into ordinary numerals using the subtraction rules when necessary: 500 + 100 + 100 + 90 + 9 Add them all together: DCCXCIX = 799.
For example, an X with a “–” written over it means 10,000. If you’re not sure whether the bar is just decoration, think about the context. Would a general send in 10 soldiers, or 10,000? Would a recipe use 5 apples, or 5,000?
1 = I 2 = II 3 = III 4 = IV or IIII 5 = V 6 = VI 7 = VII 8 = VIII 9 = IX or VIIII 10 = X
10 = X 20 = XX 30 = XXX 40 = XL or XXXX 50 = L 60 = LX 70 = LXX 80 = LXXX 90 = XC or LXXXX 100 = C
LXXVII = 77 XCIV = 94 DLI = 551 MCMXLIX = 1949
MCM = 1900 MCM L = 1950 MCM LXXX V = 1985 MCM XC = 1990 MM = 2000 MM VI = 2006
If you’re learning Roman numerals for the first time, ignore this section.
VV = 5 + 5 = 10 XXC = (10 + 10) subtracted from 100 = 100 - 20 = 80
A period between the two numbers: VI. C = 6 x 100 = 600. A subscript: IVM = 4 x 1000 = 4000.
For example, xvi or XVJ, both equal 16. xvI = 10 + 5 + 2 = 17
M was sometimes written as CI) or ∞ by early printers, or as a ϕ in ancient Rome. D was sometimes written as I) Enclosing the above numbers inside additional ( and ) symbols meant multiplication by ten. For example, (CI)) = 10,000 and ((CI))) = 100,000.
