Really cool though, does every row or column have to be solve with the exact same amount of the same number on the top and bottom (including the sides)? Cos I seem to be not working the (+) level out no matter what I do.
For the + level, the sum of a row should be equal to the number on the left or right, the sum of a column should be equal to the number on the top or bottom.
Look at this image for example, for the first row 2+5+6=13, first column 2+3+7=12 and so on.
