Fill the cells so that every number is represented once in each row and column. The first cell of each outlined area contains a target sum and a mathematical operator. Combining all the numbers written within an area, using the mathematical operator, should produce the specified target sum.

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.

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.

Use this menu option to reset the entire grid and start over.