how d you turn the roman numeral number DCCXXXI into a regular number?
Start with the numeral on the left -- D which is 500.
C = 100 -- so there are two hundreds = 200
X = 10 -- three tens = 30
I = 1
500 + 200 + 30 + 1 = 731
This site has a great explanation.
http://www.yourdictionary.com/crossword/romanums.html