Introduction: Mathemagical Card Trick
How to perform a common magic trick whether you're a magician or a mathematician.
Step 1: Get a Friend
Ask a friend to randomly select a card from a deck of 21 cards. Have them memorize this card and return it to the deck without revealing it to you.
Optional: Have them shuffle the deck themselves!
Step 2: Lay the Cards in 3 Columns
Start by creating three columns of 7 cards each by:
First, lay the top 3 cards in a row from left to right. (picture 1)
Then add a second row on top the first . (picture 2)
Continue adding rows in this manner until each column has 7 cards. (picture 3)
Step 3: Identify the Column
Have the friend select which column their card is in.
Without changing the order of the cards in this column, gather it into your hand face down, followed by the other two columns on top.
Note: The order of cards in the other two columns no longer matters.
Step 4: Again and Again
Repeat Steps 2 and 3 beginning with cards from the top.
Repeat a third time.
After the third time doing this process the card your friend selected will be the last card in the column they chose.
Memorize this card!
Step 5: Blow Their Mind!
Randomly shuffle the cards into a deck. Begin flipping cards over one by one face up until your friend's selected card is revealed. Impress them with your mathemagical knowledge by identifying the card.
11 Comments
9 years ago
Isn't this like the 21/9 card trick?
10 years ago
does this actually work?
10 years ago on Introduction
very nice...but whats the mathamatic calculation works on it...can u explain..please..?
11 years ago on Introduction
Thanks for this magic
12 years ago on Introduction
nice
12 years ago on Step 5
that girl's very pretty :$
I knew this trick from a children magazine I used to read when I was a child
13 years ago on Introduction
You can also multiply the piles of cards of 7 up to as many as possible(which is seven,by the way)and it still works. You may have to experement at first to find how many times you need to do steps 2 and3. Good trick too.
13 years ago on Introduction
Just tried this trick and it's amazing.... love things like this.
13 years ago on Introduction
It never is in the middle column for me, but it's always the last card in the column it's in, am I doing something wrong?
14 years ago on Introduction
Wow this is really good!
14 years ago on Step 5
Oh my god, this is awesome