Positive brain game. Suitable for adults and children. 6 puzzles per page. 250 easy.250 medium. 250 hard. 252 extreme. Thick paper. Glossy cover. Killer Sudoku 6x6 (Sum-do-ku, Sums Number Place, Kikagaku Nampure, Sums Sudoku, Samunamupure) divided by a smaller rectangle of 2x3 cells. The entire playing field consists of 36 cells. It is necessary to fill in empty cells with numbers from 1 to 6, each of the numbers should appear only once in each row, column and 2x3 rectangle. The sum of all numbers in the cells indicated by dashed lines should correspond to the number printed in the corner.Killer sudoku may be called or searched with the following phrases or names: sudoku, sum sudoku, killer sudoku books, times killer sudoku, sumdoku, sudoku books, easy killer sudoku, times killer sudoku books, killer sudoku puzzles, puzzle, the times killer sudoku books, times ultimate killer sudoku books, sudoku 9x9, killer sudoku puzzle books, killer puzzle, sumoku sudoku, sudoku puzzels, sudoku game, sudoku puzzle books, daily killer sudoku, daily sudoku killer, sudoku puzzles, sudoku for kids, easy sudoku puzzles, times killer sudoku solutions, super sudoku, daily sudoku, game sudoku, sudoku tips, sudokus, how do you play sudoku, play sudoku, sudoku solver, how to do sudoku, the times ultimate killer sudoku, play killer sudoku, sudoku answers, ultimate killer sudoku, how to play sudoku, sudoku rules, sudoku challenge, how to solve sudoku, sudoku puzzle solver, su doku, jigsaw sudoku, sudoku solution, sudoku easy, simple sudoku, sudoku solutions, sumoku puzzles, sudoku puzzles hard, sudoku addition, sudoku board game, greater than killer sudoku. I hope you enjoy these puzzles. Best regards, Basford Holmes