Killer Sudoku Keeping Brains Active

-100 puzzles-Hard Level-With full Solutions-Just add a PencilThese 100 Killer Sudoku puzzles will really put your brain power to the test as you "exercise the cob-webs" with these Hard Killer Su-doku puzzles. The puzzles use the same 9x9 grid as a regular Sudoku, but have an extra mathematical element. The aim is not only to complete every row, column, and cube so that it contains the digits 1 to 9, but also to make sure that the outlined sections, called cages, add up to the number given in each cage.