- Start with the 0's and 9's inside the grid, 6's on the edges and 4's in the corners.
- Analyze all clues one by one. There is always another step somewhere!
- Every new square you paint might become a useful clue later on.
- Never guess! Paint squares only if you are sure they must be filled and mark squares with an "X" only if you are sure they must be empty.
Note: There is only one unique solution for each puzzle.
When solving on paper
- Use a soft erasable pencil and a high quality eraser.
- Shade squares lightly so numbers remain visible after the squares are painted.
When playing on a computer
- Use Preferences options in toolbar for a better personal playing experience.
- Use Smart-fill Curser to speed up the game. Move cursor with mouse or arrow keys and paint squares with the spacebar or by double clicking cursor edge with the mouse.