## Oct 14, 2008

### Tricks For using Curious Maths

Yet many of the greatest magic tricks ever seen rely heavily on maths to make them work. Tricks,Secrets and Curious Maths.In this section we explore some of the best tricks so that you can amaze your friends.

Recurring Number Magic

Effect
You write down the following 8 digit number on a piece of paper:

1 2 3 4 5 6 7 9

Then ask a friend to circle one of the digits. Say that they circle number 7.

You then ask your friend to multiply the 8 digit number by 63, and magically the result ends up being:

1 2 3 4 5 6 7 9
x 6 3
7 7 7 7 7 7 7 7 7

with the answer as a row of the chosen number 7.

The Secret
When your friend circles a number, you need to multiply the chosen number by 9 in your head - if 3 was chosen you would work out 3 x 9 = 27. Then you need to ask your friend to multiply the 8 digit number by the number you have just worked out. In the case of 3 being chosen you ask your friend to multiply 12345679 by 27 and you magically get the answer 333333333.

THE NAME OF THE CARD IS...

Effect
You secretly predict which card will be chosen. Then you ask a friend to randomly select a number and count down that many cards in the deck. At first this card doesn't match your prediction, but after a few comical adjustments, the name of the card mysteriously appears!

Things you need
A deck of playing cards
A calculator
Paper and pencil

Preparing the trick
Put the 10 of Hearts in the eighteenth position down from the top of the deck.

The Secret
Announce that you are going to predict which card will be chosen from the deck. On a piece of paper, write: THE NAME OF THE CARD IS Fold the paper so that your friend doesn't see what you've written and put it aside until later. Ask your friend to:
1. Enter a 3-digit number into the calculator. (The first digit must be larger than the last digit.) Example: 845
2. Reverse this number and subtract it from the first number. -548 3.

Add the digits in the answer. 297 2+9+7=18 The digits will always add up to 18!
Tell him to count down that many cards in the deck. It will be the 10 of Hearts.
Finally, ask him to open the piece of paper and read your prediction.
He'll read, "THE NAME OF THE CARD IS".

Say that you were in such a hurry that you forgot to finish your prediction. Then make these adjustments and his card will mysteriously appear!
-cross off the H in THE
-cross off the AME in NAME
-cross off the T in THE
-cross off the CD in CARD
-change the I in IS to a T by crossing the top

leaving THE TEN OF HEARTS

The Mysterious Aces

Effect
Three aces will magically appear when the great Mathematical Forces are called.

Things you need
A deck of cards

Preparing the trick
Pick out the aces and any 8. Then count down seven cards and place the 8 with the four aces underneath it. (In other words, the 8 is the eighth card and the aces are 9th, 10th, 11th, and 12th cards down.)

The Secret
Ask a friend for a number between 10 and 20. (Be careful 10 works but 20 does not!) Deal out that number of cards into a pile one at a time. Ask your friend to add the digits of that number. Return that many cards to the top of the deck one card at a time. Turn over the top card and it will be and it will be an ACE. (Very cool!!) Set this Ace aside and put the small pile back on top of the deck. Repeat the trick two more times and get two more aces. Finally, pretend to ask the Lords of Maths for a sign as to where the other ACE is. Pretend that they tell you to turn over the top card. (It will be an 8) Count down that many cards and there will be the final ACE!!! (A quick example...count out 15 cards one at a time... then put six back one at a time...and turn over the top card .... An Ace!!!)

Number Card Magic
Make 5 cards the same as these:

Card A 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
Card B 2 3 6 7 10 11 14 15 18 19 22 23 26 27 30 31
Card C 4 5 6 7 12 13 14 15 20 21 22 23 28 29 30 31
Card D 8 9 10 11 12 13 14 15 24 25 26 27 28 29 30 31
Card E 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Get your friend to choose any number from the cards without telling you the number, but to tell you all the cards it appears on. You should be able to quickly say what number was chosen. How?

Get a friend to write down 2 numbers less than 20, one under the other without you seeing them. then your friend makes a third number by adding the first 2 together and write it below the first two. Then make a fourth number by adding the second and third, a fifth by adding the third and fourth, and so on, until there is a column of ten numbers. Now if you look at the numbers you can quickly give the total of the column. .

All you do is multiply the seventh number by 11, in the example below it is 142 x11.

Example 14+9+23+32+55+87+142+229+371+600 =1562

You can multiply by any number by 11 very quickly in your head - How? The secret is to multiply the number by 10 first and then add the number to the first result. For the example above - 10 x 142 = 1420 (the really easy bit - just add 0 to the end), then add 142 to 1420 which gives us the answer 1562 (even that bit's not too difficult either!).more mathematical tricks