I took a year off after high school and I have decided to go to college this fall. So... I need some self study material for everything before calculus. I have found a few pdf's online and this site has been a great help as well. I found some recommendations for books in the archives here, one book in particular https://www.amazon.com/Algebra-Trig...sr_1_6?ie=UTF8&s=books&qid=1198992899&sr=8-6" Does the edition of a book matter for my purposes? There are also 3rd and 4th editions but cost 6 or 7 times as much as the 2nd... Can you recommend any other books or materials for reviewing pre calculus math? Is there anything else I should try to learn before calculus like writing proofs? Thanks for any help.