Killer Sudoku (also called Sum Sudoku, Sumoku, Addoku, or Samunamupure) is a kind of hybrid puzzle that combine Sudoku and Kakuro puzzles. Like a regular Sudoku, the rows, columns and 3x3 box contain the digits 1 thru 9. In addition, the dotted lines indicate areas, called cages, which also contain a set of non-repeating digits. If you add up the digits in a cage, you get the sum shown in its clue.This Killer Sudoku Puzzles book is packed with the following features:- 1000 Puzzles from Easy to Hard for everyone in 3 Difficulty Levels: 333 Easy, 334 Medium, 333 Hard.- Answers to every puzzle are provided.- Each puzzle is guaranteed to have only one solution.- Six puzzles per page (8.5 x 11 inches).- Includes free bonus puzzles you can download book (Fitness for your brain: Word Search With Hidden Message: Train your brain anywhere, anytime! - 102 Puzzles for Adults and Seniors).