My hunch is that the hardest thing for you will be explaining why you dropped out of the working world and went to law school. "For unexplained purposes" won't fly on a b-school app.
Seriously, ideally you can show that you have made careful decisions (they don't need to have been perfect, just not reckless), and that an MBA is now the nextlogical step. If law school merely looks like a diversion that you decided to take for the heck of it, they may wonder if your approach to b-school is the same. So, be sure that you can articulate why exactly it is that you want to go to b-school now, after going through law school.
Your GPA will certainly make it harder (and may add to adcomms' thinking that this was a casual lark for you), but at least you're showing improvement over time. You'll need to provide a solid reason why your grades haven't been better.
I don't know how much a calculus class would help, but it certainly won't hurt IF you can do well in it. If you have absolutely no quant or business background, consier also taking something like an accounting or an econ class. Those subjects will help you not only demonstarte your analytical skills, but also let you show that you're serious about business topics.
Veritas Prep | GMAT Prep | MBA Admissions Consulting | Co-author, Your MBA Game Plan
Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
For a limited time, receive access to five Veritas Prep Computer Adaptive practice tests when you purchase a Veritas Prep GMAT book! Buy Now!
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.
Veritas Prep Reviews