What is the roman numerals for the number nine.
The I roman numeral is equal to the number 1:
I = 1
The X roman numeral is equal to the number 10:
X = 10
Nine is equal to ten minus one:
9 = 10 - 1
IX is equal to X minus I:
IX = X - I
So the roman numerals for the number 9 is written as IX:
9 = IX