I would be curious how one overcomes the guy in the back with his own calculator. Other than having the people on stage just enter their numbers without stating them, which doesn't seem as clean to me, I just don't see a way around it without resorting to formulae.

Pm me if you have ideas on this as we don't want to talk specifics in this open forum, please.

Lee Darrow, C.Ht.
http://www.leedarrow.com

I think it's very clean to not have them say what number they are putting in or what "sign" they are using (multiply, divide, subtract, or add). It makes more sense to me, adds a more hidden aspect to it and keeps the performer from being able to know the final number before it is presented.

If you stop thinking like a performer and think like a layperson, I think you'll find that it makes perfect sense and actually enhances the effect (if performed well, of course).

Jonathan Grant