So it's Super Bowl XLV (why do we use roman numerals but we don't use metric).
So it's (X=10, L=50, V=5 so is it 65, NO, X before L means* a minus (who knows why), so 50-10= 40; then V following L means to add 5 (must be new math), so we have 40 + 5 = 45) Super Bowl 45. Wouldn't it be simply to say that vs Super Bowl XLV.
Anyway welcome to Super Bowl 45 Sunday. Remember we are having a small pre-game party at TYF.
The use of the subtractive principle has always been optional. Its systematic use is fairly modern. For example, it's acceptable to use IIII instead of IV, as is usually done on clockfaces (to "balance" their left and right halves, so we're told).