Cut the knot: learn to enjoy mathematics
A math books store at a unique math study site. Learn to enjoy mathematics.
Google
Web CTK
Terms of use
Privacy Policy

More Mathematics
CTK Exchange

Games to Relax
Guest book
Recommend this site

Sites for teachers
Sites for parents
Manifesto: what CTK is about Buying a book is a commitment to learning Things you can find on CTK Email to Cut The Knot Recommend this page

Lights Out

Lights Out is a commercially marketed (by Tiger Electronics) product whose analysis admits a linear algebra framework analogous to that of Merlin's Magic Square puzzle. It consists of a 5×5 array of buttons that may be in one of two positions: on or off. Pressing a button changes its state and that of its vertical and horizontal neighbors. For a given configuration, the task is to turn all the buttons off (out.)

 
Buy this applet

The Theory

Copyright © 1996-2008 Alexander Bogomolny
Search:
Keywords: