There are a few excellent resources for this including Mathematical Wizardry by Harry Lorayne, Self Working Number Magic by Karl Fulves, and the bible of this genre of magic... Mathematics, Magic & Mystery by Martin Gardner. If you want a bit more in depth explanation see Magical Mathematics by Persi Diaconis. The later is a bit more advanced. They key is making teh routines fun and to not seem mathematical.
Some great effects in magic are, in fact, mathematical in nature such as Powerball by Richard Sanders which is a version of the classic Age Cards. You'll also find some stunning pieces in the Barrie Richardson books that are mathematical. Even effects like The Pennies by Giovanni Livera fall into this.
Answered at 09:43pm on October 31st, 2013 by timtrono (69 karma)