The ideal gift for su doku enthusiasts. Posing an even greater challenge than Fiendish Su Doku puzzles, this bumper collection of more than 360 puzzles is for hard-core Su Doku solvers. Selected from the pages of The Times these puzzles will keep even the most eager enthusiasts entertained for hours. Killer Su Doku, takes Su Doku to the next level. The puzzles use the same 9x9 grid but there is a double challenge. The aim is not only to complete every row, column and cube so that it contains the digits 1-9, it is also necessary to ensure that the outlined cubes add up to the same number. Puzzles in this collection are taken from Times Killer Su Doku Books 4, 5 and 6.