You might like to look at some of the packages on the following web-site.

http://www.tech.plym.ac.uk/maths/res...X/mathaid.html

They are not strictly Linux but you may well find them useful. They vary in depth from reasonably basic to quite advanced. As one of the co-authors of the material, and if you find them worthwhile, I would be grateful if you would email a response to the address on the web-site. Maths is a wonderful subject once you have mastered the basics. Good luck!