What is the Roman numeral for the number 1?

The Roman numeral for the number 1 is represented by the letter "I". This numeral system, which originated in ancient Rome, uses specific letters from the Latin alphabet to signify values. Each letter corresponds to a particular number, and "I" is uniquely assigned to represent the value of 1, making it foundational in the Roman numeral system.

The other letters represent different values: "V" stands for 5, "X" for 10, and "L" for 50. Understanding the basic symbols and their values is essential in interpreting and working with Roman numerals effectively. Thus, "I" is distinctly the correct representation of the number 1 in this numeral system.