Sorry 
for I did mean IXB not 1XB.
And I was compleatly sober when I edited that pic.
Allthough in Roman numerals IX = 9 so I guess you could say I was a little bit right for I had 1=1 and X = 10 so the letter ( number in my case

) to the left of the next letter you subtract so 1-10=9. :|\

:rotfl:
...............................
runs as crowd throws rotten tomatoes.