Why are Roman numerals not commonly used in writing numbers like the Hindu-Arabic numerals?

The correct answer is: The Roman numerals do not employ place value, so calculations are difficult to perform using these numerals.

Explanation:

The Hindu-Arabic numeral system is a positional base-10 system that uses place value (units, tens, hundreds, thousands, etc.) along with a symbol for zero. This positional system makes performing arithmetic operations such as addition, subtraction, multiplication, and division straightforward using standardized algorithms (like long addition or long division).

In contrast, the Roman numeral system is an additive (and subtractive) system that does not use place value or a symbol for zero. Numbers are represented by combining letters (such as I, V, X, L, C, D, M). Because the value of a digit is primarily fixed and not dependent on its position in a positional grid, doing complex mathematical calculations directly with Roman numerals is extremely cumbersome and inefficient compared to the Hindu-Arabic system.

Therefore, Hindu-Arabic numerals became the standard for writing numbers and performing calculations globally.