What is the Roman numeral representation of the number 26?

The Roman numeral representation of the number 26 is represented as XXVI. In Roman numerals, the symbol 'X' stands for 10, so two 'X's (XX) together represent 20. The symbol 'V' stands for 5, and the symbol 'I' stands for 1. Therefore, when you add the values together—20 (XX) plus 5 (V) plus 1 (I)—you arrive at 26, which is correctly expressed as XXVI.

This understanding of how both addition and the placement of symbols work in Roman numerals confirms XXVI is the right representation for 26. The other options do not add up to 26: XXV equals 25, XXVII equals 27, and XIX equals 19.