Amazing Prediction

First Step: Spectator is asked to shuffle the deck, then remove any twelve cards of his choice from the pack and to further shuffle these twelve cards. Whilst this is being done the magician writes a prediction on a piece of paper he places face down on the table...

Method

After the first step, the spectator now takes any four cards from his selected twelve and lays them in a row face up on the table, the remaining eight cards are put with the rest of the pack. This is now taken up, and from it cards are dealt onto each of the face-up cards so as to bring its value to ten. For instance, if a four then six cards are to be dealt on top of it. All picture cards, however, are valued at ten so no cards are put on these.
This having been done, the total value of the four cards is ascertained. For example, supposing the four face-up cards happen to be the Three of Hearts, the Seven of Clubs the Jack of Spades and the Four of Diamonds, their total value would be twenty-four. The card which lies at that number is now counted down to in the pack that remains. When it is turned over, amazingly matches the original prediction.
This self-working card trick requires no skill and can be done with a borrowed pack as long as the pack is complete (has no missing cards).

How is it done?

The spectator shuffles the pack and removes any twelve cards and whilst he shuffles these you note the bottom card of the pack remaining; this is the prediction card. Write the name of this card on the paper and put it to one side. Tell the spectator to remove any four cards discarding the rest. Drop the bulk of the pack on top of these, this brings your prediction card ninth from the bottom. The spectator lays out his four cards and deals on each one, enough cards to make up ten. The total of the four face-up cards is obtained and this number counted down to and it will be the card you previously predicted.