Binary? ? ? ???????????????????

[angeliccanary]

Can't you just mark it with binary opposed to the beautiful color play array thingamajig.

[audrey]

@angeliccanary Binary would definitely work as a representation! However, using the grid with different rows makes it easiest to see how many times the light has been "changed" (turned on or turned off), which is helpful in observing that you want an odd number of flips (and thus a perfect square) and solving the problem from there.

[debbie]

@audrey Thank you @audrey