How to subtract the Roman numerals: CDLXXIX - CDXLIII = ? Solve the mathematical operation of subtraction like the Romans were calculating, without using Hindu-Arabic numbers
The operation written with Hindu-Arabic numerals:
479 - 443 = ?
The Romans did not have the Hindu-Arabic numbers.
Steps and explanations below, without using any Hindu-Arabic numbers.
1. Simplify the operation.
Cross out the common symbols in the numerals of different signs.
The matching numerals / symbols are colored the same.
CDLXXIX - CDXLIII =
LXXIX - XLIII 2. Substitute for subtractives.
Substitute for any subtractive groups of symbols in the roman numerals; that is, 'uncompact' them using only the additive notation.
LXXIX:
IX = X - I = V IIIII - I = V IIII = VIIII
LXXIX = LXXVIIII
XLIII:
XL = L - X = XXXXX - X = XXXX
XLIII = XXXXIII
3. Cross out (remove) any symbols occurring in both strings.
LXXVIIII -
XXXXIII =
LVI -
XX
4. Get rid of all the symbols in either string.
Using the additive notation, convert larger symbols to smaller ones and then cross out the common symbols that occur in both numbers.
The larger symbols that are being converted, written in additive notation:
L = XXXXX;
LVI -
XX =
XXXXXVI -
XX =
XXXVI CDLXXIX - CDXLIII =
XXXVI
The operation written with Hindu-Arabic numerals:
479 - 443 = 36
The Romans did not have the Hindu-Arabic numbers.
The Romans also did not have the concept of negativity with their numeral system.
What we now consider to be a negative number for them was just another number, for example a debt owned, which would rather be a plus on the creditor's account.
Roman numerals addition and subtraction, online calculator
Automatically perform simple math calculations with Roman numerals, using the online calculator. Learn how to add or subtract Roman numerals, the right way, like the Romans were calculating. Without the help of Hindu-Arabic numbers. Step-by-step explanations.