Well, you need two math classes to graduate no matter what you go into. And (though I'm not going into business/management, and hence know very little about the requirements) I'm guessing that additional math will be necessary for your degree, though likely not the types of proofs you'd encounter in some of the more pure math courses.
That being said- I'm 99% sure MIT does not actually offer a degree in business, but rather in management (
http://web.mit.edu/firstyear/2010/ch...ses/index.html). And Sloan is awesome, so that's still fine and dandy if that's the route you want to take in the business world. However, you should also look here (
http://mitsloan.mit.edu/undergrad/academics.php) where it talks about the academics involved in a management degree- note that "Mathematical analysis and modeling" is at the top of the list. I'm just concerned that if you don't like / aren't good at math, MIT might not be the best place for you. The school as a whole tends to be very fond of its numbers.
EDIT: Also, here are the requirements for a management degree:
http://mitsloan.mit.edu/undergrad/management-core.php