Roman Numerals 101
Now there are some new rules. Or breaking of the old rules.
Up till now you could not use more than three (or four in the case of IIII) of the same letters after each other.
You did not represent a number as XXXXXXX. Remember?
Well it is time to break that rule. MMMMMMM is a valid number representing seven thousand. That is one way you can represent the big numbers.
The other way is to use lines above the previously defined letters.
V represents five thousand.
X represents ten thousand.