Roman Numerals
I = 1
V = 5
x = 10
L = 50
C = 100
D = 500
M = 1,000

Roman Numerals - Examples
1 = I 11 = XI 21 = XXI
2 = II 12 = XII 25 = XXV
3 = III 13 = XIII 30 = XXX
4 = IV 14 = XIV 40 = XL
5 = V 15 = XV 49 = XLIX
6 = VI 16 = XVI 50 = L
7 = VII 17 = XVII 51 = LI
8 = VIII 18 = XVIII 60 = LX
9 = IX 19 = XIX 90 = XC
10 = X 20 = XX 99 = XCIX