Reddit mentions of Schaum's Outline of Discrete Mathematics, Revised Third Edition (Schaum's Outlines)

you don't need any math for CS50


amazon lists these as its best sellers

https://www.amazon.com/Best-Sellers-Books-Discrete-Mathematics/zgbs/books/13913

there's this -- MIT's Open Course Works -- Mathematics for Computer Science

https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-042j-mathematics-for-computer-science-fall-2005/readings/

https://courses.csail.mit.edu/6.042/spring17/mcs.pdf

this has lots of problems to solve https://www.amazon.com/Schaums-Outline-Discrete-Mathematics-Outlines/dp/0071615865/ref=sr_1_5?ie=UTF8&qid=1501439754&sr=8-5&keywords=discrete+math

Rosen's Discrete Mathematics and Its Applications is the classic (which I haven't read), but if you want to avoid spending yet another $130 on a text, you might want to check out the Schaum's Outline of Discrete Math.

I have a few quibbles with the organization of the Schaum's. (I see no reason, for instance, why relations should be taught before Propositional Calculus and Boolean Algebra.) But it's a good resource, especially if you cover up the answers to the solved problems so you can get instant feedback on how well you understand the concepts.

But as a general rule, I wouldn't worry too much about Amazon ratings of textbooks. A lot of the ratings come from disgruntled students who hated the class, hated the teacher, and take their frustrations out on the textbook. You have to take these with a grain of salt.

(Note: I wrote this elsewhere)

Discrete Mathematics. It teaches the basics of the following 5 key concepts in theoretical computer science:

• function
  
• set
  
• recursion
  
• proposition
  
• proof
  
  When you master these concepts, you will see that all hairy, formal definitions boil down to functions, sets, and propositions (with quantifiers). Recursion appears in many interesting structures in computer science, as well as in proofs of theorems (which are themselves propositions).
  
  I don't know of any good online introduction to discrete math, but here are a few book ideas.
  
  
• For a good textbook on discrete mathematics, check Schaum's Outline of Discrete Mathematics. It's also cheap.
  
• For a less textbook-ish overview written in an entertaining manner, Discrete Mathematics: Elementary and Beyond is my personal favourite.
  
• If you want to learn-by-doing, then The Haskell Road to Logic, Maths and Programming teaches you discrete math by having you manipulate discrete math concepts in the programming language Haskell. Here is a good free online Haskell tutorial.

For discrete mathematics you could check out this. It's closest to a "For Dummies" book on the subject that I can think of.