i like this as a condensed summary of different math concepts spanning from elementary level to high school level. there are some concepts that i did not remember learning exactly as it is taught in this book, and many lessons and concepts that remind me of parts of my education i’d forgotten. also, regarding how i see this book being potentially useful as reference is, for one, as a reference to someone taking a comprehensive exam in a higher level math course like trig or algebra, though additional practice examples might be necessary . or additionally, i could see this being a helpful resource for a parent or teacher helping a child or student with school work and needing a refresher on concepts that are learned progressively.