Book excerpt: When you buy this book you get an electronic version (PDF file) of the interior of this book. Become a master in solving CalcuDoku 9x9. After solving all the puzzles in this book, you will be a CalcuDoku Pro. You start with easy CalcuDoku puzzles and you gradually build your way up to extremely difficult CalcuDoku puzzles. Once you pick up this book, you won't be able to put it back down. You have been warned! CalcuDoku 9x9 - Easy to Hard is a collection of 276 puzzles: 72 easy CalcuDoku 9x9 puzzles 72 medium CalcuDoku 9x9 puzzles 72 hard CalcuDoku 9x9 puzzles 60 extra logic puzzles The goal of CalcuDoku 9x9 is to fill the grid in with the numbers 1-9 such that: Each row contains exactly one of each number. Each column contains exactly one of each number. Each bold-outlined group of cells (cages) contains numbers which achieve the specified result using the specified mathematical operation (+, -, ×, ÷). Sometimes the sign +, -, × or ÷ is omitted, in which case you also need to find the correct sign. Numbers may repeat within a cage. I guarantee that every logic puzzle in this CalcuDoku puzzle book has been carefully checked to ensure that each puzzle has only 1 solution. None of the puzzles in this book will appear in any of the other English PuzzleBooks.net books. CalcuDoku is also known as Square Wisdom, CanCan, MinuPlu, Mathdoku and Calcu-Doku.