The number 999 can be represented by the Roman numeral CMXCIX
999 = CMXCIX
CMXCIX
999 = CMXCIX
999
CMXCIX
The Roman numeral IM means -1+1000 = 999
In todays notation of Roman numerals they represent: 999
Under today's rules now governing the Roman numeral system it is DCCCLXXXVIII = 888 and we now considered 999 to be CMXCIX but the ancient Romans would have worked out the equivalent of 999 as DCCCCLXXXXVIIII which can be abridged to IM meaning -1+1000 = 999
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.
It is: DCCCCLXXXXVIIII = 999 although some would say it is DCCCLXXXVIII = 888 because under today's rules now governing the Roman numeral system 999 is now considered to be CMXCIX but the ancient Romans would have worked out the equivalent of 999 as DCCCCLXXXXVIIII which can be abridged to IM = -1+1000 = 999
999
To add 777 and 999 in Roman numerals, you can first convert the numbers to their Roman numeral equivalents. 777 is DCCCLXXVII and 999 is CMXCIX. Method 1: Add the two Roman numerals: DCCCLXXVII + CMXCIX = MDCCC LXXVI Method 2: Convert both numbers to their Arabic numeral equivalents, add them together, and then convert the sum back to Roman numerals: 777 + 999 = 1776, which can be written as MDCCLXXVI in Roman numerals.