DTM Force is a way to force any number with the aid of a normal iPhone calculator. All the audience will participate with their own cell phones and do all the operations with you. Is possible to use a borrowed iPhone. No app only a clever method. In the performance you will see how to force day month and time of the performance that is the more powerful force to perform with the method, but you will force any number, like the serial number of a borrowed bill (that you change) your fantasy will find different way to use the method. Enjoy.