What is the Arabic numeral equivalent of the Roman numeral IX?

The Roman numeral IX corresponds to the Arabic numeral 9 due to the way Roman numerals are structured. In Roman numerals, letters represent values: I equals 1 and X equals 10. When a smaller numeral appears before a larger one, it indicates subtraction. Therefore, IX can be interpreted as 10 (X) minus 1 (I), resulting in 9.

This understanding is crucial when decoding Roman numerals, as it helps differentiate between situations where values are added versus subtracted. In this case, IX signifies a specific instance of subtraction, establishing that its Arabic equivalent is indeed 9.