When you buy this book you get an electronic version (PDF file) of the interior of this book. Killer Sudoku is a fun and addicting logic puzzle game that combines Sudoku with an addition math game. Killer Sudoku is a fun way for kids to practice addition facts. Killer Sudoku teaches your child logical thinking and deductive reasoning skills, even at a young age. Killer Sudoku improves critical thinking and making quick decisions based upon available evidence. Killer Sudoku is a brain game that helps to train the brain of your child. In addition, Killer Sudoku demands attention to detail - noticing patterns, spotting opportunities, and finding the right moment to make a move. Killer Sudoku is not only fun and interesting – it might just help prepare your kids for better success in school and in life. Killer Sudoku For Kids 8x8 - Easy to Hard is a collection of 141 puzzles: 36 easy Killer Sudoku 8x8 puzzles 36 medium Killer Sudoku 8x8 puzzles 36 hard Killer Sudoku 8x8 puzzles 12 easy Killer Sudoku 9x9 puzzles 21 extra logic puzzles The goal of Killer Sudoku is to fill in the empty cells, one number in each, so that each column, row, and region contains each number exactly once. The sum of all numbers in a cage (indicated by the dashed lines) must match the small number printed in its corner. No number can be repeated within a cage. I guarantee that every logic puzzle in this Killer Sudoku book has been carefully checked to ensure that each puzzle has only 1 solution. Killer Sudoku is also known as Sums Sudoku, Sumdoku, Sum Doku, Addoku, Killer Su Doku, Samunamupure, Kikagaku Nampure, Samu Nanpure, Sums Number Place.