Magic square
This puzzle consists of the numbers 1 to 81. The sum is equal per Row and Column. The sum is always: (1 + 81) / 2 * 9 = 369.
(1 + 81) / 2 = 41 is the average value of a position in the puzzle.
In the gray boxes, the sum of the empty positions is given per row and column. In this example, the sum of the three empty positions in row 3 is: 171. The available numbers are given at the top.
Copyright © Sudokuplaza