Sudoku Classic - Number Puzzle

1. Choose a difficulty and start a 9x9 puzzle tailored to your skill level. 2. Fill each row, column, and 3x3 box with numbers 1 through 9 without repeating any number. 3. Add pencil marks to note candidate numbers in empty cells and refine them as you deduce. 4. Tap Hint to receive logic-based guidance when you are stuck without revealing the whole solution. 5. Toggle error checking, use undo and redo to adjust moves, and apply strategies like singles and elimination. 6. Complete daily challenges, beat your best times, and track statistics to improve over time.