The Challenge on the Back of the Cheerios Box

We went to visit my parents last weekend. On Saturday morning, I got up before the fella and went in to breakfast. There was a plate of Cheerios on the table. I thought they'd been spilled, but as it turns out, it was a logic puzzle.

On the back of the current Cheerios box, there's a challenge:



Take away six Cheerios, but every row and every column must have an even number of Cheerios left.

My father, then my mother, had attacked this first. Then they tried it out on me. None of us figured it out, and I need to say here that we are a family of very intelligent people. (You just have to trust me on that one, sorry.) My father had even tried Googling for the answer but couldn't find it in such a way that didn't require him to fill out mailing list info. So we were stuck. In fact, we were drafting letters to General Mills telling them about the irritating typo on the back of their cereal box.

A bit later, in comes my fella. He sits down, asks about the Cheerios. We tell him. He stares at it for a bit, occasionally poking a Cheerio, here and there. Meanwhile, we start talking about how positively careless and cavalier those cereal box people are, how they shouldn't allow a problem like this onto the back of the box without thoroughly checking it, and don't you think there's a better way to spend a morning than to --

"I got it."

Huh?

Yeah. He got it in about three minutes.

(Jerk.)

Here's the answer:

Step 1



Step 2



Step 3




There you have it. And I didn't even ask for your contact information first.