**The symbols used in Roman numerals are:**

I ---> 1; V ---> 5; X ---> 10; L ---> 50; C ---> 100; D ---> 500; M ---> 1000

**Rules for the system are :**

**a)** If a symbol is repeated, its value is added as many times as it occurs:

i.e. II is equal to 2, XXX is equal to 30, CC is equal to 200

**b)** A symbol is not repeated more than three time. But the symbols **V, L** and **D** are never repeated.

**c)** If a symbol of smaller value is written to the left of a symbol of greater value, its value get added to the value of the greater symbol.

i.e. VI is equal to 5 + 1 = 6; CXX is equal to 100 + 10 + 10 = 120

**d)** If a symbol of smaller value is written to the left of a symbol of greater value, its value is subtracted from the value of the greater symbol.

i.e. IV is equal to 5 - 1 = 4; XC is equal to 100 - 10 = 90

**e)** The symbols **V,** **L** and **D** are never written to the left of a symbol of greater value, i.e. **V, L** and **D** are never subtracted. The symbol **I** can be subtracted from **V** and **X** only. The symbol **X** can be subtracted from **L, M** and **C** only.