Please, recommend me a book (or books) on basic math/pre-algebra that really explains how math works from the inside out. What I mean by that is a book that goes really deeply into exploring math giving you true understanding of what's going on behind the scenes so to speak. For example, why the long division method even works, why when dividing one fraction by another fraction is supposed to be carried out the way it is, why dividing by zero doesn't really make much sense, why a negative number multiplied by another negative number gives a positive number and stuff like that. So a book that gives the basis for basic math and arithmetics. Not like the books which only explain how to superficially perform math operations and algorithms. I looked into the for dummies series, but they are all like that, don't provide you with that kind of explanation.