You’ll be delighted with the splendid effect which you achieve in such an easy manner.
You place the Ace, Two, Three and Four of (say) Clubs on the table in a square formation. You cover two cards with two jumbo cards. One by one all the cards assemble under one jumbo card. You try to repeat the ‘assembly’ without the jumbo cards but the regular cards do not move. You turn over three cards and they are seen to be all blank. The other card is the 10 of Clubs, the sum of all the cards!