Why Roman numerals don't have the number zero?

Solution:

The Roman numerals are a unique system of numerical notations used by the Romans represented by a set of certain letters.

Roman Numeral system is based on the pattern and not on a technique. They have specific signs to represent different numbers.

I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000

For subsequent numbers, the sign is repeated and not added.

For example:

• 1 = I and 2 = II 
• 10 = X and 20 = XX

But the word NULLA (the Latin word meaning "none") used to represent the number zero as 0 does not have its own Roman numeral.

Thus, there is no zero(0) in the Roman numeral system.

Why Roman numerals don't have the number zero?

Summary:

Roman numerals start to count from one and didn't need to have a zero in their additive system as it was basically designed to estimate the prices of goods and trading business.