suggested books ??

Do lots and lots of sudoku. It totally help me become more alert in my studies and pick things up faster when teacher is explaining or when i'm reading an unfamiliar text. You can get sudoku books from book stores. As for the maths part, go to any bookstore and you can buy books that says higher math ,college math , or precalculus. If you can't afford it, go to the library. By the way , i studied precalculus on my own without teacher just by reading and understanding from the book. When i don't know something i ask my friends who are in engineering course. So if i can do it , you can do it too.

tey sudoku puzzle. it is a number-placing logic game that will test your mental skills.

Higher Mathematics,linear algebra.And so on.