Kakuro is aJapanese numerical puzzle, which is a rectangular grid with black and white cells. White cells form vertical and horizontal blocks of not more than 9 cells. The goal of the puzzle is to place the numbers from 1 to 9 in the corresponding white fields based on the following rules:
- The digits in the same horizontal or vertical block never repeat.
- The numbers in black cells are equal to the sum of all the numbers in a block on the right (or bottom) of the cell.
The numbers in the cells can be placed with either a left or a right mouse click. Each time you click the numbers will increase or decrease. When the "specified number" option is selected, you can put the numbers with just one click by selecting it from the panel that appears after clicking. You can also use the keypad, i.e., the number keys and the spacebar arrows to navigate through the cells.
For the convenience of players, duplicate numbers in white boxes are highlighted in red automatically. The numbers in black cells are also highlighted red if the current placement of numbers within the block does not allow any options for the remainingl cells or if the sum of the numbers does not add up.
The numbers corresponding to the sum of the digits will be highlighted in green.