In this puzzle, you must fill the grid with the numbers 1-8 with the following rules:

– each number can only be used once.

– A pair of adjacent numbers cannot be in the grid horizontally, vertically, or diagonally next to each other. (ex. “1” and “2” cannot be next to each other in the grid)

ex.1

“2” and “3” is next to each other, so this is not a solution.

ex. 2

“1” and “2” is diagonal to each other, and “4” and “5” is horizontal to each other, so this is not a solution.

There are a total of 40320 possibilities to fill the grid. So instead of trying them all at random, the trick is to realize that “1” and “8” must go into the two center squares. No other number can go into the center squares because it will be next to 6 other squares. Once you figure that out, it will be obvious where “2” and “7” will go, followed by the rest.