TITLE: Encyclopedia of mathematics (?)
QUESTION [18 upvotes]: I'm currently studying an engineering degree and I got fascinated about math. The issue here is that I want a single source to learn mathematics; I mean, I want to learn every single math topic pretty well. I found the Encyclopaedia of Mathematics, Hazewinkel. This is a collection of 10 volumes and 3 supplements. I just want to know if you consider this worth it for 2300 usd. If not, what source could you recommend to me? I know I can read a lot of sources and learn math; however, I dream of buying a single source and learning all of it. Thank you :)

REPLY [4 votes]: I guess you are rather new to math. Consider this: the Dutch logician Evert Beth made a bold estimate of the extent of math knowledge. He guessed in 1947(!) that an academic math student would be offered just about 1% of the available knowledge. Davis and Hersh (The Mathematical Experience) estimated (in 1984) the number of theorems published every year at 200,000. So that is what you are up to if you want to learn it "all".
As mentioned by others you don't have to spend a penny to learn math. It is all available on the net. Forget encyclopaedia and single source, you need multiple sources: books, lectures, exercises and foremost practice, practice and practice. Check out MOOC: Edx.org, coursera.org, Khan academy, MIT OpenCourseWare. Lots of educators publish their lecture notes, look for .edu sites. Excellent for beginners: PDF lecture notes of Paul Dawkins.