The Grid by Richard Wiseman DVD & Gimmicks (DVD731)

The spectator selects a card from a deck of numbered cards.

The
magician then deals out four hands of cards and asks the spectator to
guess which hand adds up to the same number he has chosen.?Incredibly,
the spectator is correct. The chosen hand does add up to his selected
number. But that’s not all. Each of the other three hands also reveals
the chosen number.

The four hands are quickly arranged into a 4 x
4 grid to form a magic square. Each column, diagonal, row now adds up
to the chosen number. Even the four corners total the number.

Finally,
the cards are turned over to reveal a message that also predicts the
chosen number. Complete with special deck. Totally self-working. Easy to
reset. Different numbers can be selected.