Cups and Balls

Name That Name

Effect: You reveal a thought-of name.
Secret: Cut a slot in the top of a box with a removable lid and tape a small box on the inside. Write the same name on 10 slips of paper. Put them in the box and replace the lid. Hand out 10 blank slips and ask spectators to write a name on their slip. The slips are put in the box through the slit. They actually go into the hidden box. Remove the lid for just one slip to be chosen. As all the slips are the same it is easy to reveal the name chosen.

Going Up!

Effect: Two tumblers are suspended from a newspaper balanced on a magic wand.
Secret: Bend a paper clip around your magic wand to form a U shape. Tape the wire to a newspaper.
The newspaper is shown and then folded into a long flat tube. The secret wire should be on the side of the
newspaper nearest to you. Place the newspaper across two tumblers, making sure that each prong of the wire
goes into the tumblers. Place your wand between the tumblers and lift it towards the newspapers.
The newspaper will be lifted – but so will the tumblers.

In The Red

Effect: You instantly identify a selected card. Secret: Place all the black cards on top of the red cards and you are ready. Spread the cards face down and ask someone to take any card. Make sure he takes one from the top (black) half of the pack. He then replaces it anywhere in the pack but you make sure he replaces it somewhere in the bottom (red) half of the pack. Look through the cards and somewhere in the red cards will be one black card. That is the chosen card. Remove it and show it to everyone.

Fruit Transformation

Effect: An orange transforms itself into an apple.
Secret: Carefully cut the peel from an orange, as shown in the illustration and scoop out all the fruit. When
the peel has dried put an apple inside it. Hold the peel closed and it appears you are holding an ordinary
orange. Cover the orange with an handkerchief. When you remove the handkerchief, take the orange peel off
the apple but keep it hidden within the material. Casually drop the handkerchief (with the orange peel still
hidden) behind something on your table or put it in your pocket, as you display the apple.

Disappearing Coin

 Effect: A coin disappears from your hand in spite of the fact that several people check it is there.
Secret: Show the coin on the palm of your hand and cover it with a handkerchief. Go to several people and ask them to feel the coin under the handkerchief. The last person you approach is (unbeknown to the rest of the audience) your secret assistant. He pretends to feel the coin but actually takes it off your palm. You can now pull the handkerchief away with a flourish and your hands are shown completely empty.
The coin has disappeared.

The Self-propelled Ball.

Effect: A ball rolls across the table until you tell it to stop.
Secret: Under the table cloth is a small ring attached to a length of strong thread. The thread runs across the table to where your secret assistant is sitting. A small ball is placed on the table. It must go into the concealed ring. On your word of command your assistant pulls on the thread and the ball moves. You then pick up the ball and hand it to a spectator. As you are doing this, your assistant pulls the ring from beneath the cloth and hides it.

Match Maker

Effect: Matches appear in an empty box.
Secret: The matchbox drawer is secretly prepared by cutting it in two. One section is longer than the other.
Put the two pieces of drawer in the box and fill it with matches. To show the box empty pull the long part of the divided drawer from the box. The matches will remain in position inside the cover and the drawer will appear to be empty. Close the drawer. To show the box full push the drawer from the other end. This moves both pieces of the drawer and the matches make their appearance.

Ring Of Deception

Effect: A bangle passes on to a length of rope tied securely to your wrists.
Secret: You need two identical bangles and a long piece of soft rope.
Secretly put one of the bangles on your arm, hidden under your coat sleeves. Have two spectators tie each
end of the rope around your wrists. Show the bangle to ensure that it is solid. Turn your back, quickly pull
the secret bangle down your sleeve on to the rope and hide the bangle just shown in an inside pocket.
Turn back to face the audience and show the bangle tied on the rope.

Calculated Discovery

Effect: You remove cards from your pocket to the value of a chosen card.
Secret: Put the Ace of Clubs, Two of Hearts, Four of Spades and Eight of Diamonds in your pocket. Have
the pack shuffled then put it in your pocket.
Ask someone to name a card. The four cards you hid can represent any card. For the Six of Clubs you take
out the Four and the Two to make six and the Ace to show Clubs. For the Queen of Diamonds take the Eight
and the Four to make 12 and point to the Eight of Diamonds and so on.

A Capital Prediction

Effect: Acapital city is chosen. Inside an envelope which has been on full view is a paper naming the city selected.
Secret: Write a capital city on a piece of paper and seal it in an envelope.
Capital cities are called and you write them down on slips of paper which are folded and dropped into a box.
In fact you write the same name on every slip – the name of the city in the sealed enveloped.
Someone picks a slip and calls out the chosen city. The envelope is opened to show you knew which city would be chosen.

That's Torn It!

Effect: A coin is wrapped in paper. You then tear up the paper – the coin has disappeared!
Secret: Place the coin on the paper, just above the centre. Fold the top portion of paper down over the coin.
Fold the right side of the paper around to the back. Do the same with the left side.
Lastly, fold the bottom portion back. This procedure leaves the bottom edge of the packet open. Hold the
paper in your hand and allow the coin to slip secretly into your hand. Tear up the paper and the coin seems to
have vanished.

Indestructible Handkerchief

Effect: A large safety pin is pulled through a handkerchief without tearing it.
Secret: Ask someone to hold a handkerchief out taut. Push a safety pin through the material, near the edge
of the handkerchief. Hold the pin by the tail end and turn it towards yourself. Now pull the pin to the right.
When you stop, push the pin forward so it goes back through the material. You have moved the pin from one
place to another without tearing the handkerchief. What actually happens is that the material runs between
the bar and the head of the pin.

Marvellous Memory

Effect: You appear to memorise the order of a pack of cards.
Secret: Cut a small hole in the bottom right corner of your card case.
Ask someone to shuffle the cards and hand them back to you. Look through the cards quickly, then place
them in the case. Hold the case in front of you and you will see the index of the first card through the hole.
Name this card and pull it from the case. Do the same with a few more until you think you have proved that
you really did memorise the order of the cards.

Homing Coins

Effect: Four coins disappear then magically return.
Secret: On two sides of a triangular stand is a ledge to hold four coins. Those on one side are loose, the
others are glued in place. The stand is on your table with the loose coins on show. Pretend to take the first
coin away but really let it fall behind the stand. Put the imaginary coin in a paper bag. Do the same with the
other coins. As you cover the stand with a scarf, tip the stand backwards. Blow up the bag and burst it.
Whisk the scarf away and the coins have returned.

Binary Numbers Magic Trick

Here is a trick that you can do at home.

1. Cut out the 5 cards below. You are now ready to do the trick.
2. Give the 5 cards to a friend, and ask them to pick a secret number between 1 and 31, and to give you back all the cards that have their number on it.
3. You can figure out their secret number by adding together all of the first numbers on the cards they gave back to you. For example, if they gave you back the top and middle card, then their number would be 20, because the first numbers on these cards are 16 and 4, which add up to 20.

Why does it work?

Remember how to write the numbers from 1 to 31 in binary? See the chart below if you forgot. The sequence of 1's and 0's in a binary number tell us which powers of 2 add up to make the number. For example, 19 = 16+2+1, so in binary we write 10011.

Now notice that the number 19 appears only on the first, fourth, and fifth cards above. That is, 19 appears on the cards with first numbers 16, 2, and 1, and it does not appear on the cards 8 or 4.

The 5 cards correspond to the powers of 2. The numbers that are on the first card (with "16" as the first number) are the ones that have a "1" in the 16's position when we write it in binary. The numbers on the "8" card are those with a "1" in the 8 position in binary. And so on for the other cards. So, when you add up first numbers on the cards that a "secret" number is on, you are adding up the powers of two that add up to the secret number!

Counting in Binary:

Math Telepathy

This is a stunning magic performed by the computer.

Follow the instructions. In the process you will be requested to compute the difference of two natural numbers (although on second thought, the omission of the decimal point appears not at all important.) See that you do not make a silly mistake. The magic fails in the face of ill preparedness. (As is well known in the magic circles, if a spell may go wrong, it will.) So, if you wish, you can use a calculator to compute that difference. In any event, it may be a good idea to double check your result.

Number Guessing Game

In this simple game, your computer does all the work. You only have to press one of the buttons, "Yes" or "No". This is how you play. At the beginning (or after pressing "Reset"), you think of a positive integer less than 100. At any time, the computer will display a set of numbers. In response, press either "Yes" or "No" depending on whether your number is on the screen or not. After a while the computer will guess your number. See for yourself.

Calendar Magic

With the second button on the left reading "Set", drag the cursor inside the table and select a square array of dates. Once you are satisfied with your selection, click the button. The label will change to "Play". While playing pick up dates inside the select area. One in each row and in each column. Sum up selected dates. The sum that also appears in the lower right corner does not depend on selection of dates inside the square but only on the square itself. See if you can verify or even prove this.

Arithmetic Magic Matrix

Select exactly one square in every row and in every column and check that the sum (or the product) of numbers in the selected squares does not depend on your selections. Can you explain why? How are these tables constructed? Try small sizes, 2×2, 3×3, etc.