Nine-o-gram Hints

Look for rows or columns where the numbers almost fill the entire line. Those are often the easiest places to begin and can anchor the rest of the puzzle.

Check the outer rows and columns. Large numbers near the edges can force certain squares to be filled no matter what — especially when the total of the clues is close to 9.

When you know a square must be empty, mark it clearly. Eliminating possibilities is just as powerful as filling squares.