What is half of 999 in Roman numerals?

Answer 1

In accordance with the rules governing the Roman numeral system made up during the Middle Ages and centuries after the Romans had quit England, 999 in Roman numerals is today reckoned to be CMXCIX and half of this would work out as CDXCIXS (499.5)

But in all reality the Romans themselves would have most probably wrote out 999 simply as IM and half of this work's out as SD (-0.5+500 = 499.5)

Note that the Roman numeral for a 1/2 looks like the letter S and its Latin name is 'semis' which means a half.

Answer 2

Half of 999 in Roman numerals is CDXCIX.