Electronic magic does not have to be expensive.This is a fantastic trick!!! You can use it in a show, in a restaurant, bar, with friends. Imagine the following: You first show a PREVISION envelope and place it on the table aside. Nobody will touch it. Next you show a normal calculator, and show that it makes all functions. Hand it to a spectator and ask him to digit the year he was born. Multiply by the day he was born. Divide by his wife age. and some more calculations as you like, and numbers chosen by the spectator, random. Next, you ask her to calculate 22 percent of that number, by pressing X , 22, %.
There is a result, and ask the spectator to open the envelope, and find a dollar bill, and check the serial number. The number is the same of the PREVISION. Note: The calculator model could be different of the photo.