about maths course during a Gap year

<p>I was wondering if anyone had any thoughts about the best ways to pursue Maths courses during a gap year after I graduate from high school. I dropped Maths in high school and now am hoping to use part of my gap year to try to plug this gap. If you have any thoughts on the best ways to do that it would be great if you could share them with me.
Also, I am considering doing a postgraduate year at a boarding school in the US - if you have any thoughts on which boarding schools have really good PG programs it would be great if you could share that with me.
Not very competitive, but great place to be.</p>