The Big Ten has 11 teams and will soon have 12. (The CIC, the academic arm of the conference, has 13.) [update: they are expanding to 14 for most sports + Johns Hopkins for Lacrosse]
The Big Twelve has 10.
The Pac-10 has 12. [They had the sense to update their name to Pac-12.]
The A-10 has 14. [Now 12 or 13 depending on the sport]
Maybe collegiate conferences should stop including the number of teams in their official name.
(Yes, I know Brand is dead. But I don't know the name of his successor at the NCAA off the top of my head.)