The rules as we now know them today governing the Roman numeral system had absolutely nothing to do with the ancient Romans because they were introduced during the Middle Ages presumably to make Roman numerals more compatible with Hindu-Arabic numerals that were gradually replacing Roman numerals at the time but there once were only two basic rules governing the Roman numeral system and they were as follows:-
Positive numerals went from left to right in descending order.
Negative numerals went from right to left in ascending order.
As for example: SXCL = -1/2-10+100+50 = 139.5
Note that: -10 is less than -1/2 and that 100 is greater than 50
As for example: SXXCL = -1/2-20+100+50 = 129.5
Note that: -20 is less than -1/2 and that 100 is greater than 50
The above examples were extracted with slight modifications from the reference book 'History of Mathematics' volume 2 by David Eugene Smith first published in 1925 and ISBN 0486 204 308
QED
998- CMXCVIII 998 is CMXCVIII in roman numerals because CM represents 900 in roman numerals, XC represents 90 in roman numerals and VIII represents 8 in roman numerals; technically this is the correct answer.
In ancient Rome the numerals of VL would have been perfectly acceptable as being the equivalent of 45. But the real rules governing the original Roman numeral system were changed during the Middle Ages and as a result the equivalent of 45 in Roman numerals today is considered to be XLV.
Decimals cannot be written in Roman numerals. Roman numerals correspond to whole, real, positive integers.Cannot be roman numerals:1/5-5-1/50.15-0.15Can be roman numerals1510501005001000
111- CXI 111 is CXI in roman numerals because C represents 100 in roman numerals, X represents 10 in roman numerals and I represents one in roman numerals. Because of this, XI is 11 in roman numerals; so this will be the correct answer.
1800- MDCCC Why is MDCCC 1800 in roman numerals; because M represents 1000 in roman numerals and DCCC represents 800 in roman numerals, this is the correct answer.
CXXXXV is not a correctly written Roman numeral. The individual numerals within it are real numerals but according to the rules of writing Roman numerals 'no numeral can be written more than three times in succession.' So, XXXX is not allowed. The numerals you have written add up to 145 and the correct Roman numeral for this is CXLV
998- CMXCVIII 998 is CMXCVIII in roman numerals because CM represents 900 in roman numerals, XC represents 90 in roman numerals and VIII represents 8 in roman numerals; technically this is the correct answer.
In ancient Rome the numerals of VL would have been perfectly acceptable as being the equivalent of 45. But the real rules governing the original Roman numeral system were changed during the Middle Ages and as a result the equivalent of 45 in Roman numerals today is considered to be XLV.
Decimals cannot be written in Roman numerals. Roman numerals correspond to whole, real, positive integers.Cannot be roman numerals:1/5-5-1/50.15-0.15Can be roman numerals1510501005001000
111- CXI 111 is CXI in roman numerals because C represents 100 in roman numerals, X represents 10 in roman numerals and I represents one in roman numerals. Because of this, XI is 11 in roman numerals; so this will be the correct answer.
1800- MDCCC Why is MDCCC 1800 in roman numerals; because M represents 1000 in roman numerals and DCCC represents 800 in roman numerals, this is the correct answer.
Decimals cannot be written in roman numerals. Only whole real numbers.
The five letter word MIMIC can be formed from Roman numerals but as the individual numerals are in the wrong order it isn't a real Roman numeral.
1700- MDCC The reason because 1700 is MDCC in roman numerals, here is the reason; M represents 1000 in roman numerals and DCC represents 700 in roman numerals, this has been the correct answer.
800- DCCC 800 is known as DCCC in roman numerals because the rule of roman numerals goes over three digits which means DCCCC is not 900 in roman numerals 900 is CM.
1976
In brief, this system of numeracy had nothing to do with the Romans because the system was conceived by the mysterious Etruscans who once ruled the Romans. After the Romans gained their independence from the Etruscans they kept this system of numeracy which became later known as Roman numerals. The way we write out Roman numerals today differs in many respects to how the Romans actually did themselves. The real rules governing the Roman numeracy system were changed in the Middle Ages presumably to make Roman numerals more compatible with Hindu-Arabic numerals that were being introduced into Western Europe at the time.