Print this page and cut out the nine squares. Then try to arrange the squares in a 3x3 grid so that

1
Print this page and cut out the nine squares.
Then try to arrange the squares in a 3x3 grid so
that wherever two squares touch, the touching
numbers sum to zero. Be warned, however, that
there are more than 95 billion ways to arrange
the squares, of which only four are solutions.
1
1
-1
-2
Good
Bad