Answer
If the values of symbols increase from left to right then the values of the symbol on left is subtracted from the values of symbols on the right.
Work Step by Step
To interpret a Roman numeral, it involves both subtraction and addition. If the values of symbols increase from left to right, then the values of the symbol on left is subtracted from the values of symbols on the right. To explain further consider an example,
Assume a Roman numeral\[\text{CMXLIV}\].
\[\begin{align}
& \text{CMXLIV = }\left( 1000-100 \right)+\left( 50-10 \right)+\left( 5-1 \right) \\
& =900+\text{40 + 4} \\
& \text{= 944}
\end{align}\].
