For fans of Killer Sudoku, Samurai Sudoku and other variants

### 9 square grid

Way back in my Jr. High days, I had a math problem that you had a 9 square grid and you had to have the numbers add up to the same total going up, down and diagonal. There was a formula but I forgot it(senior moment). Can you help me? Thank you
jwc471

Posts: 1
Joined: 31 December 2005

### none

not sure but supose you want to add the numbers 1-100 up you take

101*50 you get 5050.

the forumula is N as a real number .5N(N+1)
Chessmaster

Posts: 191
Joined: 21 December 2005

I think jwc471 is looking to construct a 9x9 diagonal magic square...
However don't know any mathematical formula regarding it...
Probably there are some mechanical methods...
udosuk

Posts: 2698
Joined: 17 July 2005

thought so can't think of any now but i will look into it
Chessmaster

Posts: 191
Joined: 21 December 2005

Seems you're looking for Magic squares.
There are mehods to generate them.

It's well explained on Wikipedia : http://en.wikipedia.org/wiki/Magic_square
Jean-Christophe

Posts: 149
Joined: 22 January 2006