How To Read Roman Numerals

There are 7 letters that are used for the base roman numerals which are used in different ordered combinations to represent all other positive integers. They are as follows.

I – 1

V – 5

X – 10

L – 50

C – 100

D – 500 

M – 1000

In order to create the rest of the numbers they can be combined together in a particular order which denotes how they are read by signifying either addition or subtraction from the largest of the numbers indicated by whether the larger numeral comes before or after the lesser numeral

The rules are as follows 

1. The same numeral can only be repeated 3 times consecutively (e.g III = 3, XXxIII =33, CCC=300)
2. Numerals V,L and D cannot be repeated.
3. If a numeral of lesser or equal value is to the right of the original numeral they are added together. (e.g. VII = 7, XV = 15, LX = 60)
4. If a lesser value numeral appears to the left of a numeral of greater value the lesser numerals are subtracted from the greater one (e.g. IV = 4,  IX = 9, XL = 40, XC = 90)
5. V,L and D can never be subtracted from X,C and M (e.g. The Roman numeral representing 95 is XCV not VC)
6. The numeral I can only be subtracted from V and X (e.g. cannot be IC or IIM) and the numeral X can only be subtracted from L, M and C

Numbers 1-10

I – 1

II – 2

III – 3

IV – 4

V – 5

VI – 6

VII – 7

VIII – 8

IX – 9

X – 10

Breaking down the following numbers 1 – 10

1. I (a base numeral)
2. II (I is followed by I so 1+1 = 2)
3. III (1+1+1 =3)
4. IV (I which is lesser (1) precedes V which is greater (5) so 1 less than 5 or 5-1=4)
5. V (a base numeral 5)
6. VI (V is followed by I which is lesser so addition 5+1 = 6)
7. VII (V is followed by II so addition 5+2 = 7)
8. VIII (V is followed by III so addition 5+3 = 8)
9. IX (I is before X and is lesser so subtraction 10 – 1 =9)
10. X (a base numeral 10)