Easy Maths Magic Tricks Pdf Download
Osman Blunt
Select a number without telling me but point to the card or cards it appears on.
I will tell you the number you have in your mind!
For example, if someone chooses the number 5 and they point to the two cards this appears on, simply look in the top left hand corner of the cards and add the numbers (4 +1).
Maths magic tricks can energise any maths class and create a sense of wonder and curiosity about maths. You can introduce them as problem-solving tasks and challenge children to demystify them so they are valuable activities for developing critical thinking skills. THOANs are probably the easiest to start with (THink Of A Number).
Share the following 10 tricks with children and explain how they are done.
Encourage them to practise with family and friends but remember to tell them that a magician never reveals their secrets!
Just as every teacher should have a collection of jokes at the ready, every teacher should also have a collection of maths tricks up their sleeve to show children.
Encourage children to practise and personalise a couple of tricks with a maths partner, building up to a performance in front of a small group; add a bit of performance theatre to it as confidence grows.
Within a whole-class session ask children to take on the role of a mathemagician - ready to impress everyone with marvellous memory feats and spell-binding maths wizardry!
John Dabell is a teacher with over 20 years teaching experience across all key stages. He has worked as a national in-service provider and is a trained OfSTED inspector.
I am interested in magic tricks whose explanation requires deep mathematics. The trick should be one that would actually appeal to a layman. An example is the following: the magician asks Alice to choose two integers between 1 and 50 and add them. Then add the largest two of the three integers at hand. Then add the largest two again. Repeat this around ten times. Alice tells the magician her final number $n$. The magician then tells Alice the next number. This is done by computing $(1.61803398\cdots) n$ and rounding to the nearest integer. The explanation is beyond the comprehension of a random mathematical layperson, but for a mathematician it is not very deep. Can anyone do better?
"You, my friend, are about to witnessthe best card trick there is.Here, take this ordinary deck of cards,and draw a hand of five cards fromit. Choose them deliberately or randomly,whichever you prefer--but donot show them to me! Show them insteadto my lovely assistant, who willnow give me four of them: the 7 of spades,then the Q of hearts, the 8 of clubs, the 3 of diamonds. There is one card left in your hand, knownonly to you and my assistant. And thehidden card, my friend, is the K of spades."
This was fascinating for me. Somehow the man takes a bagel and with one cut arrives with two pieces that are interlocked. Whether this qualifies as "magic" I dunno (it's hard to say once the trick's been explained), but it sure seems like it to me.
It doesn't hurt that I love bagels, and have the opportunity to perform this with friends/family/non-math people and can teach a little about problems/topology/counter-intuitive facts about the universe.
One of the best mathematical tricks is what happens when you cut a Mobius strip in the middle. (Look here) (And what happens when you cut it again, and when you cut it not in the middle.) This is truly mind boggling and magicians use it in their acts. And it reflects deep mathematics.
(I heard this from Eric Demaine and from Shahar Mozes.) If we hang a picture (or boxing gloves) with one nail, once the nail falls so does the picture. If we use two nails then ordinarily if one nails falls the picture can still hangs there. Mathematics can come for the rescue for the following important task: use five nails so that if any one nail falls so does the picture.
Have a volunteer shuffle a deck of cards, select a card, show it to the audience, and shuffle it back into the deck. Take the deck from him, and fling all of the cards into the air. Grab one as it falls, and ask the volunteer if it is his card.
1 in 52 times (this is the deep mathematics part), the card you grab will be the card the volunteer selected. Even most statisticians should be amazed at this feat. Just make sure you never perform this trick twice to the same audience.
The "trick" is that every entry is an integer, and that the pattern of 1s quickly repeats, except upside-down. If you were to continue to the right (and left), then you would have an infinite repeating pattern.
Incidentally, if anyone can provide a reference as to why this all works, I'd love to see it. I managed to prove that all of the entries are integers, and that they're bounded, and so there will eventually be repetition. However, the repetition distance is actually a simple function of the distance between the two rows of 1, which I can't prove.
A late addition: The Fold and One-Cut Theorem. Any straight-line drawing on a sheet of paper may be folded flat so that, with one straight scissors cut right through the paper,exactly the drawing falls out, and nothing else. Houdini's 1922 book Paper Magic includes instructionson how to cut out a 5-point star with one cut. Martin Gardner posed the general question in his Scientific American column in 1960.
For the proof, see Chapter 17 of Geometric Folding Algorithms: Linkages, Origami, Polyhedra.We include instructions for cutting out a turtle, which, in my experience, draws a gasp from the audience. :-)
Now inform your audience that you are going to look briefly at each remaining element of $S$ and remember exactly which elements you saw, and determine by process of elimination which element of $S$ was removed.
You can use hamming codes to guess a number with lying allowed. For example, here is a way to guess a number 0-15 with 7 yes-or-no questions, and the person being questioned is allowed to lie once. (The full cards are here).
I would like to thank all the contributors on this page. I have been putting together a new Math-a-Magic show for the 9-12 grade level and have found some fantastic material here. If I get a decent video of the show I'll be sure to post a link here so you can play the "What concept is behind this trick?" game.
I have modified some of your ideas severely. For example. Craig Feinstein's suggestion was a commercial effect that asks the volunteer to pick one of a hundred different cities typed out on ten cards. The volunteer finds the city's name on two different cards which the magician looks at casually. You can then instantly tell him the name of the city he has mentally picked.
Taking a deck of cards, you mention you have a prediction about these cards. That means it is very important to give the cards a really random shuffle.You then give your volunteer half the deck and you both shuffle your half decks thoroughly. Tell your volunteer to take a small amount(5-15) of cards from his half of the deck, turn them upside down and give them to you. you do the same to him (doesn't matter how many cards you turn upside down as long as there is some left in your hand)You then both shuffle the cards you have received into the deck in your hands in there upside down state. so at this point both people will have some cards right side up some cards upside down. You will follow the same procedure two more times. It doesn't matter how many or what cards he or you are turning upside down and giving away. After all this is done put both half decks of cards together again (IMPORTANT: turn your entire half deck over when you place it on top of his)Now you spread the cards out across a table top. They should be a seemingly random mix of upside down and rigtside up cards. You then unfold your prediction slip which says something like: 11 cards will be black, 15 cards will be red, 6 will be clubs and 5 will be hearts and the hearts will also form a royal Flush!
They will be astounded by your amazingly detailed prediction. What happens is that all the face up cards are the ones that were originally in your half deck. This trick is self working. All you do is to pick out which cards you want in your half of the deck and place them at the top of the deck to start. Then just give him the random bottom half of the deck and you keep the pre-set ones.
Here is a card trick from Edwin Connell's Elements of Abstract and Linear Algebra, page 18 (it can be found online). I always do this trick to my undergraduate number theory class in the first minutes of the first day. A few weeks later, after they've learned some modular arithmetic, we come back to the trick to see why it works. I quote from Connell:
"Ask friends to pick out seven cards from a deck and then to select oneto look at without showing it to you. Take the six cards face down in your left handand the selected card in your right hand, and announce you will place the selectedcard in with the other six, but they are not to know where. Put your hands behindyour back and place the selected card on top, and bring the seven cards in front inyour left hand. Ask your friends to give you a number between one and seven (notallowing one). Suppose they say three. You move the top card to the bottom, thenthe second card to the bottom, and then you turn over the third card, leaving it faceup on top. Then repeat the process, moving the top two cards to the bottom andturning the third card face up on top. Continue until there is only one card facedown, and this will be the selected card."
When I do this trick, I always use big magician's cards (much easier for an audience to see), but a regular deck works too. To get to the trick faster, I skip the first part and just pick 7 cards myself, showing them all the cards so they see nothing is funny (like two ace of spades or something). I then spread the cards in one hand face-down and let a student pick one and show it to everyone else but me before I take it back face down. When the student is showing the cards to the class I move the rest of the cards behind me so that before I get the card back I already have the rest behind my back.
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