Omigod! Only 1,355 days until Super Bowl XLVI! For those a little rusty on the whole Roman numerals thing, the Indianapolis Star provides this helpful advice:
X = 10
L = 50
V = 5
I = 1
Don't add the numbers up; 66 is not the correct answer (by the time that Super Bowl rolls around, we'll be building another new stadium).
There's a trick: If a letter is placed before another letter of greater value, you subtract the lower-value letter.
So it's: L--X+V+I = 46. Or, in English: 50--10+5+1 = 46.
I don't know why the NFL doesn't use plain numbers. It drove me crazy when I was a kid sitting in a theater, trying to figure out what year a movie was made as the Roman-numeraled copyright date came up with the end credits.