How do Roman Numerals work?

To understand how Roman numerals work, it is important to recognize that a numeral is a symbol used to represent a number. In contrast to the Hindu-Arabic system, where each digit represents a unique value, the Roman numeral system assigns different letters to represent specific values. For example, I represents one, V represents five, X represents ten, L represents fifty, C represents one hundred, D represents five hundred, and M represents one thousand.

In the Roman numeral system, numerals are combined by stringing them together. To represent a larger number, the numerals are added together. 

For instance, 83 in Roman numerals is written as LXXXIII.

Here's how it is broken down:

L represents 50
XXX represents 30
III represents 3
So, LXXXIII represents 50 + 30 + 3, which equals 83 in Arabic numerals.

To prevent long and cumbersome numbers, the Romans also allowed for subtraction when a smaller numeral precedes a larger one. For example, 24 is represented as XXIV, instead of XXIIII. However, a numeral can only precede another numeral that is equal to ten times the value of the smaller numeral or less. Thus, I can only precede and be subtracted from V and X.

Since the largest numeral used by the Romans was M, or 1000, it was impractical to write extremely large numbers using a string of 1000 Ms. To avoid this problem, the Romans used a bar called a vinculum over numerals to indicate that it should be multiplied by 1000. This allowed the Romans to write large numbers using a more efficient notation, such as writing 6000 as V̄Ī and 1,000,000 as M̄.