This book is timeless, dealing as it does with the fundamentals of mathematics, and in a way which is accessible to almost anyone. If you need a painless introduction to the field of mathematics, then get hold of a copy of this masterpiece by Frank Land. You won't be disappointed. He has a gift for making an abstruse and often incomprehensible subject not just interesting but compelling. The book is shot through with examples, even extending to an equation written in Egyptian hieroglyphics!
The mathematical level is probably somewhere in the CGSE region, but concentrates on the fundamental ideas underlying much of the subject. There are chapters on units, simple and compound, on time, on logs, pianos and spirals, on geometry and shapes, on algebra, and even on things such as the Fibonacci series and the Golden Section. With over 250 pages in large format (18.5 x 25 cm) paperback (but strongly bound) it is quite a long book, and not cheap. But having read it as a teenager (er, 40+ years ago) it certainly fired my interest and should do the same for any serious-minded youngster who really wants to know what maths is all about. I don't think one could do better, even now.