NOTE:
CALCUDOKU 8x8 is a logical-mathematical game in which you have to fill a 8x8 square with the digits 1, 2, 3, 4, 5, 6, 7, 8. You can't have the same digit in the same row or column.
For each region a number and a mathematical operation indicate that, applying that operation to all the digits in the region (note that the order doesn't matter), you must obtain that result.