Help
Fill the cells using the numbers 1 to 9. The numbers in each horizontal block of white cells should add upp to the total in the black square to the left. The numbers in each vertical block should add upp to the total in the square above. No number should be repeated within a block.
If you are unsure of the correct solution for a particular cell, you can click this button to choose notation mode and note possible number candidates. Write the same numbers again to remove the notes. Click the button again to close the notation mode.
Reveal and check
To confirm that you have entered the correct solution, click the Check menu option. You can check a single cell or the complete grid solution. Incorrect numbers are marked in red. Blank cells will be ignored. Click the Reveal menu option to reveal a single cell or the complete grid. Incorrect numbers will be corrected.
Reset
Use this menu option to reset the entire grid and start over.
