During my school days I was a very keen student of mathematics. But circumstances led me to opt for commerce at the college level. Now I wish to continue learning mathematics on a self study basis. First of all I would like to brush up my pre-college mathematics (which included basic algebra, number theory, euclidean geometry, basic trigonometry).
I started with the book What is mathematics? but found it to be too rigorous.
Can somebody recommend books which explain all elementary concepts, proofs, theorems in brief?