Changes

== Subtraction ==

== Subtraction ==

Letters are put in order from greatest to least.  A lesser letter occurring before a greater letter is subtraction. When subtracting, only subtracting powers of ten such as I, X, or C is allowed. You cannot subtract with V, for example. Too, you can only subtract one digit away. For example, IIX is not 8 but rather use VIII for 8. Finally, you cannot subtract one letter from another letter if it is ten times greater than it, so one would not be able to subtract X from M since M is one hundred times greater than X, yet you can subtract X from either L or C.

Letters are put in order from greatest to least.  A lesser letter occurring before a greater letter is subtraction. When subtracting, only subtracting powers of ten such as I, X, or C is allowed. You cannot subtract with V, for example. Too, you can only subtract one digit away. For example, IIX is not 8 but rather use VIII for 8. Finally, you cannot subtract one letter from another letter if it is ten times greater than it, so one would not be able to subtract X from M since M is one hundred times greater than X, yet you can subtract X from either L or C. In Roman times, while any combination of numerals which makes the appropriate number was considered sufficient, only the above method was considered proper.  

* Example:  MCMLXXXIII = 1983  

* Example:  MCMLXXXIII = 1983