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Math Magic

Classic mathematical magic, presented properly: watch it, be puzzled by it, then learn to do it yourself.

• Coming soon

  The 1089 Trick

  Reverse, subtract, add — and land on a number I already wrote down.

  I'd play this
• Coming soon

  Missing Digit Mystery

  Hide one digit. Casting out nines brings it back.

  I'd play this
• Coming soon

  Number Cancellation

  Algebra that makes your choices vanish.

  I'd play this
• Coming soon

  Kaprekar's 6174

  Any four digits fall into the same strange number.

  I'd play this
• Coming soon

  The 21-Card Trick

  Three deals, and your card finds its way to the middle.

  I'd play this