After searching the site, i found some questions like mine, but none fits my case.
I am a 11th grade student, and i have an ebook reader(kindle). I would like to know where can i find(free) content about intermediate math learning, so i could spend some spare time (when away from the computer) studying.
The ideal is .mobi's, but .pdf's are also fine.
I already looked MIT OCW pdf's, but i don't understand a lot, and i don't know from where should i start.