Rainbow Matrix by Max Maven

Here’s what happens:

The audience requires no props. The performer displays a simple chart showing numbers, and some colored markers or crayons are used to select several numbers at random. This can be done for one person, or involve choices from up to six people. It all seems beyond control, yet the outcome is predicted. And there’s bonus material: a formula by which you can use this system to yield any total, and a long-buried secret version using a deck of cards that’ll blow your mind.