2 Answers

For simple expression of numbers, it is represented by single letters that stand for the numbers one, five, ten, fifty, one hundred, five hundred and one thousand, and those letters are I, V, X, L, C, D and M, respectively. As well, numbers that are more or less than those definite amounts rely on a system that has each specific amount preceded or succeeded by lower-ranking letters to indicate a number that is less than or more than the base letter. A few examples are:
3 - III... three ones. 4 - IV... one LESS THAN five. 13 - XIII... ten plus three ones. 36 - XXXVI... three tens plus five plus one. 475 - CDLXXV... one hundred LESS THAN five hundred plus fifty plus two tens plus five.

It equals 48 not 38

See: http://www.novaroma.org/via_romana/numbers.html