What does the dash mean over the symbols here? How to convert these Roman numerals to numbers?
Textual equivalent of the image:
$$\overline{\text{M}}\,\overline{\text{L}}\,\overline{\text{V}}\text{MCCLXXIX} \text{ et } \overline{\text{C}}\,\overline{\text{M}}\,\overline{\text{V}}\text{CCCLXXXII}$$
The bar means multiplying by $1000$, so the numbers in the picture are $1056279$ and $905382$.