This Book is the result of a unique experience: a research mathematician teaching in an elementary school.
The third part is an excu.
The second part tells about the teaching principles the author distilled from his experience.
It tells about a fascinating discovery made by the author -- that elementary Mathematics has a lot of depth and beauty, and that the secret to its teaching is in understanding its deep points.
The first part of the Book discusses the nature of Mathematics and its beauty.
This Book is the result of a unique experience: a research mathematician teaching in an elementary school