Stephen BarrReseñas

"The Upside-Down Hat" by Stephen Barr is a heartwarming story about a boy named Joey who helps a homeless man. It's good to have in a classroom because it teaches empathy, kindness, and the importance of looking beyond appearances.

Creative story and award winning illustrations. A good story of perseverance and making do with what you have.

Quality has a quantity of its own, according to Stephen Barr's accessible account of topology and related mathematical concepts.

This book is excellent for an intelligent adult looking to return to mathematical investigation, without building on a recent "core study" of algebra, geometry, and differential calculus. The issues of exotic topological surfaces, networks, continuity and discreteness, and set theory are all approached in a candid manner with efficient examples. Despite the informality of the prose, anyone reading this like a novel will get very little out of it. This is really a math book, and it often requires the reader to take considerable time to assimilate new ideas.

Part of Barr's approach to the abstractions of topology is to encourage the reader to construct paper models to approximate some of the surfaces introduced. These exercises are quite worthwhile. Although there is no "test," the book does include a number of interesting puzzles applying the concepts discussed.