This addition to the successful Times Killer Su Doku series adds the challenge of arithmetic, taking Su Doku to a new and even deadlier level of difficulty. The puzzles use the same 9x9 grid as Su Doku. The aim is not only to complete every row, column and cube so that it contains the numbers 1-9, it is also necessary to ensure that the outlined cubes add up to the same number as well. With 200 new Moderate, Tricky, Tough, and Deadly Killer Su Doku puzzles.