What is the secret behind this math card trick?

  • Thread starter Thread starter Whalstib
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around a math card trick, exploring its underlying mechanics and whether it relies more on mathematical principles or memory techniques. Participants share their experiences and analyses of the trick's effectiveness.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the trick works consistently, having tried it multiple times without failure.
  • Another suggests that the arrangement of the cards is crucial, but struggles to articulate the reasoning without becoming unclear.
  • A participant provides a detailed breakdown of the card arrangement and calculations involved, indicating that the trick relies on specific card values and their positions.
  • Some participants argue that the trick may not fundamentally involve math, proposing that it could be more about memory techniques instead.
  • One participant mentions that demonstrating the trick while explaining the process can enhance the illusion of complexity for the audience.
  • Another emphasizes that the key aspect of the trick is the relationship between the number of cards held and the top card of the stack.

Areas of Agreement / Disagreement

Participants express differing views on whether the trick is primarily mathematical or a memory-based illusion. There is no consensus on the underlying mechanism of the trick.

Contextual Notes

Some participants' explanations depend on specific assumptions about card values and arrangements, which may not be universally applicable. The discussion includes unresolved elements regarding the effectiveness of the trick based on different approaches.

Whalstib
Messages
119
Reaction score
0
I've spent a few minutes...or more<G> trying to crack this one...

http://www.metacafe.com/watch/535213/math_card_trick_revealed/

...to no avail.

After trying it much becomes apparent but not the final answer.

I tried it 5 times and it worked every time!

Warren
 
Mathematics news on Phys.org
It works on how the cards are laid down. That is about as far as I can explain that without trowing gibberish!

If you like the math card tricks check out CardTrickTeacher (Mismag822) on youtube. he has a whole bunch of math card tricks!
 
It only matters the three first blocks of cards, since all the others are discarded. Suppose the cards that initiate each block are A, B and C respectively.
You have 11 - A cards in the first block, 11 - B in the second and 11 - C in the third, or 33 - (A + B + C) in the total.
Since there are 52 cards in the deck, the remaining cards are 52 - [33 - (a + B + C)] or 19 + A + B + C.
You discard 19 cards from the remaining. You have A + B + C cards.
You uncover the top cards of the first and third blocks (A and C).
You separate A + C cards from the remaining and you get B, the top card of the center block.
 
The thing is, it really doesn't involve math at all when you think about it, which makes it simpler... It's memory.

Notice he doesn't shuffle the stacks, so it may involve some math shenanigans, but its also a memory trick possibility.

I just tried it both ways, and both ways work (math and memory)
 
beaster said:
I just tried it both ways, and both ways work (math and memory)

The best part of the trick though is using the formula and telling the person you are showing the trick exactly what you are doing the whole way through. The average person will be just as baffled, if not more so. Every person I have shown it to has believed I was pulling a fast one on them even though I told them at the beginning it was purely a trick of math.
 
Yea the point of the trick is not that you know what the top card is, but that the number of cards you are holding is the same as the top card.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 31 ·
2
Replies
31
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 32 ·
2
Replies
32
Views
2K
  • · Replies 27 ·
Replies
27
Views
7K