1. ## Maths Square

Hi hope its ok to post here I have a math problem, please can someone help?
I have spent several days on it but just cannot complete it, The most I have managed to get is 7 numbers, then it just goes to pot

Using the numbers 1 to 7 only, the eight white squares that surround each shaded square should add up to the number they surround. Moreover, once completed correctly, no row nor column will contain a duplicate number within a white square.

2. There are a couple of ways to try this problem . . .

1. The way you probably have been trying is guess and check: P is probably a 7 since it is shared by the 4 largest numbers etc.

2. Setting up simultaneous equations with all 40 variables. You would need 40 equations to solve it easily but I can only see the following:

4 vertical rows that add up to the sum of (1 through 7)
4 horizontal rows that add up to the sum of (1 through 7)
9 sum of 8 variables that are surronding grey squares.

so you have 17 equations and 40 unknowns.

I think a combination of the two strategies will help you out. for example set up the equations and make some intelligent guesses and see where it takes you.

3. By the way I played around with this puzzle and p is probably not 7.

Excel could be very useful for this puzzle.
you could set up the grey squares to be sums of the surrounding squares and then start entering values.