Mental Numeracy 545 by Mark Cahill

From a borrowed deck shuffled by any spectator, deck is handed to 5 participants who each take any card they want, placing it face down in front of them and remembering this freely selected card.
A few more random cards are then mixed in with their selected card for each spectator.
The piles are now gathered up by magician, who has not touched the cards up until this point.
Magician now mixes the cards.
Cards are dealt out randomly into 4 piles, each card placed at spectators choice, their decision.
Piles are now gathered up by spectators decision in any order they choose.
Magician spreads a few cards at a time asking if anyone sees their cards.
Once any spectator says they see their card, the magician immediately knows their selection.This process of spreading over cards is repeated until all participants have seen their cards.
These cards can be revealed by the magician however they want. Example: individually, in a group, through mind reading or when you get to the last selection, a card to pocket or wallet are just a few ideas.

A true card miracle that plays to any audience, has complete audience participation, and entertains all who has seen this. Deck can be borrowed if needed or performed from a fully shuffled deck in use. All the shuffling and card selections are done before magician ever touches the deck.

Key Points:
Full deck not required
Borrowed deck any condition or your own
No stacks
No memory work
No marked deck
Spectators shuffle & mix
100% free selection of all cards
No gimmicks No crimps
Perform closeup or stage
Entertaining & audience participation