At 09:07 PM 5/30/2003, you wrote:
I've never seen this trick
before. What properties of the subsquares make this
trick work? Would it be possible to perform this trick with a
square that has
distinct entries? Entries 1 through 64?
http://www.mdani.demon.co.uk/stunt/may98s1.htm
I think it is based on Latin squares. When you pick a 4x4, and do
the procedure, you select one and only one number from each row and
column. Any such set of four numbers for a given 4x4 sum to the
same number.