Oliver wrote:
The resulting grid will have 22 ways to sum the called out number. I don't think there is an easier method using a geniunely called out number with fewer or simpler calculations.
The method described by Allerton (which is "rediscovered" in quite a few other books) is indeed very simple, but it can be improved upon. The method described in
Mindsights uses slightly simpler math and creates a square with 24 strong ways to add up to the (freely) chosen number (there are actually 26 ways, but two of them are somewhat less interesting, so I rarely point them out, in the interests of time).
In addition, the version in
Mindsights can be used with numbers of any size, which although possible with Allerton-type squares, tips off the method (try it with a larger number, such as 99, and see how "unusual" the square becomes).
But most important of all (especially to walk-around and trade-show performers) is the fact that the technique in
Mindsights can be
repeated. You can create squares for multiple people (even with the same target number), and they don't all end up looking alike.
... Doug