Magic Tricks

I have always had an interest in the use of magic squares in my programs and I have been thru a great many of them in the process of finding the right one to use. I am seeking one that combines ease of preparation and not too much memory work under pressure.
The Executive Grid adds to the ease of preparation aspect of the use of magic squares with its memory guide on the border. this built in crib is quite clever and easy to use, but, to me, what I like most about it is the suggestion on how to add an " extra number" in the equation to keep the square you prepare from looking strange and giving away the secret on larger target numbers where you have to include 3 or 4 numbers which are totally obvious as being plugged in to get to the target number and are much larger numbers than the ones used in the rest of the cells.The out of sync large numbers is a clear give away as to the method to a sophisticated audience.
Executive Grid gives you a nice way to deal with that issue and to clean up the square so all of the numbers are compatible with no jarring exceptions. To me, that technique alone is worth the price of the effect. Bravo.