Teacher Demonstration 20
Cut the Deck
Materials:
• 1 deck of playing cards (jokers removed)
Instructions
1. Show the class what is meant by ‘Cutting the Deck’.
Read all the instructions and see Teacher Notes for
the secret – it’s deceptively simple.
2. Remove the top half of the deck at any point. Tell the
class it doesn’t matter where the deck is cut.
3. Place the top half next to the bottom half.
4. Then place the bottom half on the previous top half.
5. The deck has been cut. Repeat this procedure as many
times as you like – the number of times does not
really matter at all but suggest 13 because that is the
number of cards in each suit (ie hearts, clubs etc).
Teacher Demo 20 – Cut the Deck | Page 1
© 2007 Ruben Meerman | ABC Science Online
6. The deck can be cut anywhere and any number of
times – ie in the middle, near the top or near the
bottom.
7. Let several students cut the deck for you to avoid any
suspicion that the cutting procedure matters or is
rigged in any way
8. When the deck has been cut sufficiently (13 times is a
good auspicious number), flip the pack over revealing
only the bottom card.
9. Start fanning out the pack one card at a time to reveal
they are in perfect order! Amazing!!!
10. Continue fanning into the next suit to reveal the
whole deck is in perfect order! Incredible!!! How does
it work??
Teacher Demo 20 – Cut the Deck | Page 2
© 2007 Ruben Meerman | ABC Science Online
Teacher notes
What’s the secret?
The deck is prepared in advance and is in perfect order right from the beginning of
the trick. For the most impressive result, arrange the deck so that the suits are stacked
in alternating colours eg:
♥A, ♥2, ♥3, ♥4, ♥5, ♥6, ♥7, ♥8, ♥9, ♥10, ♥J, ♥Q, ♥K,
♠A, ♠2, ♠3, ♠4, ♠5, ♠6, ♠7, ♠8, ♠9, ♠10, ♠J, ♠Q, ♠K
♦A, ♦2, ♦3, ♦4, ♦5, ♦6, ♦7, ♦8, ♦9, ♦10, ♦J, ♦Q, ♦K
♣A, ♣2, ♣3, ♣4, ♣5, ♣6, ♣7, ♣8, ♣9, ♣10, ♣J, ♣Q, ♣K
How does it work?
Cutting the deck does not affect the order of a deck of cards – it only changes the
positions of the top and bottom cards. Consider the stack of boxes illustrated below.
After the first cut, box 11 is at the bottom and box 10 is at the top but the order is
otherwise unaffected. The second cut puts box 11 back on top of box 10 – now box 6
is at the bottom and box 5 is at the top and again, the order remains unaffected.
Cutting the stack of boxes any number of times does not affect the order of the boxes.
First Cut
Second Cut
20
10
5
19
9
4
18
8
3
17
7
2
16
6
15
5
5
20
14
4
4
19
13
3
3
18
12
2
2
17
1
1
1
16
10
10
20
20
20
15
9
9
19
19
19
14
8
8
18
18
18
13
7
7
17
17
17
12
6
6
16
16
16
5
5
15
15
15
10
10
4
4
14
14
14
9
9
3
3
13
13
13
8
8
2
2
12
12
12
7
7
1
1
11
11
11
6
6
11
11
Cutting a stack of boxes does not affect the order
Teacher Demo 20 – Cut the Deck | Page 3
© 2007 Ruben Meerman | ABC Science Online