The Roman numeral XLVIII is the equivalent of the number 48. Roman numerals are actually upper case letters that are used to represent numbers. The basic Roman numerals are I, V, X, L, C, D and M, which stand for one, five, 10, 50, 100, 500 and 1,000, respectively.
A Roman numeral may be used as many as three times in succession. In XLVIII, 40 is represented by XL. The X, which stands for 10, cannot be used four times, so it is placed to the left of the L, which stands for 50, to indicate that 10 is subtracted from 50. The eight in 48 is represented by VIII, which is five plus three, or eight.