I like this effect a lot. It uses the Maurice Kraitchik Matrix concept (which has been at the center of so many great effects by people like Gibson, Maven, Becker, James, Lyons, Neale, and many others). But unlike most effects using the Matrix concept, this one is totally impromptu. So you can do it anytime someone hands you a deck of cards.
The photos include the effect description, but here is how I describe (and perform) it:
After explaining what a straight is (in poker), five spectators each choose one card from an ordinary shuffled deck. You then pass the deck around to each of them, and they remove any four cards from the deck to make a straight with their first chosen card. The choices are completely free. When all five spectators have made a straight, the five straights are laid out on the table for comparison. (I do a quick cold-reading for each spectator here, based on the values of the straight they chose). Now I remove two cards from the deck, and set them aside facedown. I give a poker chip to each spectator, and they are allowed to place their chip on any of the cards, using the Matrix procedure.
When the values of the five cards under the chips are added up, they equal (for example, 43). The two cards on the table are turned faceup -- they are a 4-spot, and a 3-spot. Forty-three.
Super easy to do, and as mentioned before, completely impromptu.
A great little booklet. New-old dealer inventory, so like new and unused, even though it is 30+ years old.