Maths prize puzzle 27 January 2017: the 21 card trick | A minimum of blind calculation
7-7-7 – The 21 Card Trick by Jon Racherbaumer – Martin's Magic Collection
21- Card Trick Tutorial - YouTube
Computer Science for Fun - cs4fn: Magic Memories Just Shuffling Along: The 21-card trick
21 Card Trick: Best Variations, History & Tutorial
7-7-7: The 21 Card Trick (Jon Racherbaumer) - Meir Yedid Magic
How to Do the 21 Card Trick- No Skill Needed | Mind Blowing Magic
Easy Magic Trick With 21 Cards for Beginners | Magic card tricks, Easy magic card tricks, Magic tricks for kids
Lisle Library District - Luck or Skill? 21 Card Trick | Facebook
21-Card Trick – Numberphile
How to Do the 21 Card Trick- No Skill Needed | Mind Blowing Magic
A Factorial Card Trick
The card trick 21 cards are taken from which viewer selects one card The 21 cards are divided into 3 piles Viewer identifies pile in which selected card. - ppt download
21 Cards Magic Trick - YouTube
How to Do a 21 Card Card Trick: 11 Steps (with Pictures) - wikiHow
Magic Trick: How To Do The "21 Card Trick" - YouTube