Addoku = Sudoku with arithmetic! Millions of Addoku and Sudoku puzzles to solve.

Addoku (also known as Killer Sudoku) is a variation on the well-known Sudoku puzzle that tests your capabilities in both logic and arithmetic. It's a regular Sudoku grid, but to fill it in you need to use your knowledge of addition.

Addoku Plus takes the arithmetic a step further, introducing subtraction, multiplication, and division.

For a change of pace, there are also regular Sudokus to be solved.

Features:

- Create and solve Sudoku, Addoku and Addoku Plus puzzles

- Millions of puzzles available

- Ten levels of difficulty

- Checkpoint and restore the puzzle state

- Undo/redo

- Progress information

- Save your unfinished puzzle and return to it later

- Online tutorial, including solving a puzzle step by step