Please forward this error screen to 158. I don’t understand it at all. Third Law of Sir Arthur C. 1089: Subtract a 3-digit number and its card tricks revealed pdf, then Multiples of Nine: A secret symbol is revealed.

Casting Out Nines: A missing digit is revealed. The Final 3 are the chosen cards. Related articles on this site: Dice. Divisibility rules for 7, 13, 91 Combinatorics and Probability.

Pick a 3-digit number where the first and last digits differ by 2 or more Consider the “reverse” number, obtained by reading it backwards. Subtract the smaller of these two numbers from the larger one. Add the result to its own reverse. Why is this always equal to 1089? 2 and 9, so the above is a 3-digit multiple of 99, namely: 198, 297, 396, 495, 594, 693, 792 or 891. The middle digit is always 9, while the first and last digits of any such multiple add up to 9.

Thus, adding the thing and its reverse gives 909 plus twice 90, which is 1089, as advertised. Pick a 2-digit number Add the two digits together. Subtract that sum of digits from the original number. Look up the symbol corresponding to the result in a special table. How can the magician predict what that symbol is? Thus, a new table must be provided each time. Several online implementation do this quite effectively, with nice graphics.

How fast can you discover the secret which makes this work? Figure out the missing digit in a large product of two integers. Effect : The magician hands out a 3 or 4-digit integer chosen by a spectator in a previous part of the show. Using a pocket calculator, another spectator multiplies that number by some secret 3-digit number which he chooses freely and keeps for himself.

The result is a 6 or 7-digit number. The spectator withholds one of those digits and reveals all the others in a random order. Ask a spectator to pick any 4-digit number and to consider the number obtained by reading it backwards. Ask how many digits there are in the final result and ask the spectator to keep one nonzero digit secret and to reveal the other digits in scrambled order. Count ostensibly on your fingers how many digits you are given to make sure you’re only missing one. You may then call the remaining digit with perfect accuracy. Guess with perfect accuracy which one of three cards was chosen.

The following effect can be repeated as many times as needed to convince the spectators that you can read their minds with perfect accuracy as they pick one of three choices. Ask a spectator to choose one mentally and remember its position. Turn around and instruct the spectator to show the other spectators which card he has chosen, then have him switch the two other cards behind your back. Now face the table again and instruct the spectators to switch cards as many times as they wish in front of your eyes. Reveal the card originally chosen by the spectator.

When you face the table again, focus of the card which is now in the middle and keep track of its position as spectators move cards around. Otherwise, the chosen card can be neither the one you had memorized nor the one you’re now seeing. Copperfield first asks you to take N steps forward and N steps back. It doesn’t matter what N is, does it? Regardless of the details of that show, it should be clear that a magician can only make predictions about outcomes which do not depend on the choices of his many spectators.

However, surprisingly many people want to believe in some irrational explanation. This is what really scares me. Each student in the class is asked to think about a small number and is then instructed to perform the following operations silently. Subtract the original number Convert this into a letter of the alphabet.