0Roman Numerals:
We know the basic Roman form of the numbers are:
1 : I = I
2 : I + I = II
3 : I + I + I = III
4 : IV = IV
5 : V = V
6 : V + I = VI
7 : V + I + I = VII
8 : V + I + I + I = VIII
9 : IX = IX
10 : X = X
Above were the basic form of Roman numerals.
These basic form should be learnt by heart.
Forming of the Roman Numerals:
11 : X + 1 = XI
12 : X + I + I = XII
13 : X + I + I + I = XIII
14 : X + IV = XIV
15 : X + V = XV
16 : X + VI = XVI
17 : X + VII = XVII
18 : X + VIII = XVIII
19 : X + IX = XIX
20 : X + X = XX
