Newspapers and similar media often feature crossword puzzles, word-searches, general knowledge quizzes, problems on word games like Scrabble and other puzzles, typically on ‘brain’ games like chess and bridge. As one who has always been fascinated by mathematics, the author offers testing examples from the world of numbers which will require a fair amount of brain-work if you are to find correct solutions. The world of numbers displays much variety and some strange traits. That world forms the first of our group of problems and then the book focuses attention on the three "p’s": palindromes, primes, and powers. Later, geometry problems and examples where numbers can be substituted for letters conclude the book. We hope readers enjoy being challenged!