This is a perfectly delightful book which will provide many hours of pleasure to the mathematically inclined child or adult. It would be a nice birthday present, for example. --Norman R. Draper, International Statistical Review, 2012 Train Your Brain is an enjoyable way to exercise your brain and spend a few spare minutes during the day. While this collection of math and logic puzzles vary in depth and complexity, they are certainly challenging enough to keep anyone engaged. I found the structure of Gratzer's book to be particularly appealing. ! I really enjoyed solving and attempting to solve the puzzles presented in this book. ! most could be solved by anyone from an advanced high school student to a college student with a solid background in mathematics. There is something for everyone in this book. --Janet Shiver, MAA Reviews, February 2012

George Gratzer is a distinguished professor in the Department of Mathematics at the University of Manitoba. He has published over 200 research publications and 25 books, including General Lattice Theory and Math into LaTex. He is a member of the Canadian Academy of Sciences and an external member of the Hungarian Academy of Sciences.