When adding or subtracting roman numerals without converting them to Arabic numbers is quite straight forward.
The first thing you have to remember is that there is NO number placement in roman numerals as there is with our ordinary Arabic system.
The Number 499 is represented by the roman numerals CDXCIX where the number 500 is represented by the symbol D. Roman numerals simply get there value by combining ALL the values of the symbols present. You do however have to be familiar with how to convert Roman numbers and the subtractive rule.
Step 
Action to be taken 
Worked Example 
1 
Write the numbers to be added. 
CDXCIX + MMMCMLIX 

2 
Identify any subtractives 

3 
Expand the numbers



4 
Combine all the same symbols, starting with the largest. 
MMMCCCCCCCCCCCCCL XXXXXXXXXIIIIIIIIIIIIIIIIII 

5 
Regroup your new answer using the subtractive rule where necessary. 
M'S (3):MMM 

Put it all together! 
MMMMCCCLXCXVIII 
This concludes our adding and subtracting Roman Numerals page. As you can see, it is indeed quite straigt forward, however it will ALWAYS be difficult if the symbols and their values cannot be remembered. It is impossible to do anything with Roman Numerals if you don't know these. Download our mnemonic to remember Roman Numbers to help your student retain these. And remember! Practice, practice, practice! Try some of our free printable worksheets  some of the crossword puzzles are quite challenging.
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