It can be but normally IV = 5-1 = 4
I don't know. I've never seen a Roman numeral with more than one lesser numeral preceding a greater numeral, as in "...CCM...". If you remove one of the C's, MCMLXXVII is 1977.
500
CCD is not a Roman numeral. C is a Roman numeral which has a value of 100. D is also a Roman numeral which has a value of 500. However according to the rules of writing Roman numerals although a C can preceed a D, to represent 400, no number should be preceed by two or more numbers of lesser value. If CCD was a Roman numeral it would have a value of 300 but the correct Roman numeral for 300 is CCC.
A Roman numeral can be considered invalid due to several reasons. These include using a repetition of the same numeral more than three times in succession (e.g., IIII instead of IV), writing a numeral in a descending order (e.g., XCX instead of C), or using a numeral that is not part of the standard Roman numeral system (e.g., A instead of I).
Because of the introduction of the Hindu-Arabic numeral system during the Middle Ages which was more efficient than the Roman numeral system inasmuch that it contained a zero symbol.
The roman numeral for 5 is V and 1 is I, since 6 is one more after 5 the roman numeral for 6 is VI.
I don't know. I've never seen a Roman numeral with more than one lesser numeral preceding a greater numeral, as in "...CCM...". If you remove one of the C's, MCMLXXVII is 1977.
500
CCD is not a Roman numeral. C is a Roman numeral which has a value of 100. D is also a Roman numeral which has a value of 500. However according to the rules of writing Roman numerals although a C can preceed a D, to represent 400, no number should be preceed by two or more numbers of lesser value. If CCD was a Roman numeral it would have a value of 300 but the correct Roman numeral for 300 is CCC.
A Roman numeral can be considered invalid due to several reasons. These include using a repetition of the same numeral more than three times in succession (e.g., IIII instead of IV), writing a numeral in a descending order (e.g., XCX instead of C), or using a numeral that is not part of the standard Roman numeral system (e.g., A instead of I).
Because of the introduction of the Hindu-Arabic numeral system during the Middle Ages which was more efficient than the Roman numeral system inasmuch that it contained a zero symbol.
LLLLTC is not a valid roman numeral. T is not a roman numeral character, nor would you preceede C with more than one L. C = 100 L = 50
The Roman numeral system needed only 7 symbols while the ancient Greek numeral system needed 27 symbols
We still use Roman numerals to a certain extent today but the Roman numeral system was replaced by the Hindu-Arabic numeral system because it contained a zero symbol thus making arithmetical operations a lot easier whereas the Roman numeral system has no zero symbol and mathematical operations were much more difficult.
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
Roman numerals gradually went out of general usage in the Middle Ages which was when the Hindu-Arabic numeral system was beginning to be used more often than the Roman numeral system.
D is 500 M is 1000