Sudoku: The best brainteaser!
Fill the empty spaces, ensuring the numbers 1 to 9 appear just once in every horizontal line and once in every vertical column. Furthermore, each number may only appear once in each block.
Click on an empty space and click on the number of your choice in the ring.
Click on PENCIL to fill in a number temporarily. Then click on PENCIL again to fill in the numbers permanently. Click on UNDO to delete the last move you made. Click on CLEAR to start the puzzle all over again. If you click on HINT, a hint will appear in red or green.
Score and bonus