Schaum’s Easy Outline Series When you are looking for a quick nuts-and-bolts overview, there’s no series that does it better. Schaum's Easy Outline of Introduction to Mathematical Economics is a pared-down, simplified, and tightly focused version of its predecessor.
I still use this book for revisions to maintain the formulas and structures in my head. I just can't force myself to work through a whole textbook on this subject again since my "passion" in Economics is the social ideas and statistical facts, and to be perfectly honest I find mathematical economics to be pseudo-science. Regardless of personal opinion, the book practical to have around: it is written in simple language, has examples, and is surprisingly comprehensive.