Digital deletions
Digital deletions is one of the original mathematical games described by John Conway in his famous 1976 book On Numbers and Games. As always with mathematical games, playing it is only part of the fun; the best part is discovering a winning strategy.

The game is very simple:
To the best of my knowledge, this is the first interactive JavaScript version of Digital Deletions to appear on the Web. If you know of other programmed versions, please contact me.

I am proud to announce that this page is referenced by the Drexel Math Forum.

Drexel reference

How to play the game
 Number of digits:
 Strategy to use:
 Choice of digits:
6 7 8 9 10 11 12 13 14 15 16 17 18 Computer starts
Computer starts
Human starts
Human starts
Easy strategy Medium strategy Tough strategy
Easy strategy
Medium strategy
Tough strategy
Human defined Random generated
Human generated
Random generated
Play the game
Click a digit to change its value. A glowing green light appears underneath the chosen digit.
If the value of this digit is After having calculated its move, the computer informs you about it with a glowing red light indicating the digit that has been changed and a panel, showing the old and the new value. Just click the digit you want to change to acknowledge the computer's move.

More Information
9 8 7 6 5 4 3 2 1 0
9 8 7 6 5 4 3 2 1 0
New game
Change the game parameters
No new game