My name is Nick Grundberg, I'm in Middle school and my question is :

Using the this square, fill in the squares using the numbers 1 through 9 just once to make all the sums equal in all directions, across, down, and diagonally.

Then tell what the sum of the magic square equals.

Thankyou!

Hi Nick,

If the sum in all directions, across, down, and diagonally is N then using the square below:

we have that

Thus a+b+c+d+e+f+g+h+i=3N. But a+b+c+d+e+f+g+h+i=45 and thus 3N=45 and hence N=15.

Cheers,
Penny