Miro and Moro, the Strips That Match

Miro and Moro are otters, and they are twins. Not almost-twins. Not sort-of-twins. The exactly-the-same kind. They finish each other’s sentences, they swim the same lazy loops, and they have spent their whole lives being mistaken for one another - which suits them fine, because it happens to be the truth.

They live in the two long strips that lie in the middle of Mayor Tila’s growing square. Miro’s strip runs along the bottom. Moro’s strip stands up the side. Each strip is a one way and b the other. And a great many visitors, glancing quickly, decide there is only one strip in there, or that the two strips must be somehow different sizes.

This is the thing that makes Miro and Moro get up from their loafing and prove a point.

“You think we’re different?” says Miro, sliding out of the bottom strip.

“You think there’s only one of us?” says Moro, popping up from the side strip.

And then they do the thing they love best. Moro turns his strip a quarter-turn - just a gentle rotation - and lays it down directly on top of Miro’s. Edge to edge. Corner to corner. The two strips cover each other perfectly, with not a whisker of overlap and not a sliver of gap.

“Same length,” says Miro.

“Same width,” says Moro.

“Same lot,” they say together, delighted, because being the same is their whole talent.

A strip that is a by b holds ab little tiles. That is Miro’s strip. And Moro’s strip - which just proved it is identical - holds ab tiles too. Two strips, each worth ab. So together they are worth ab and ab, which is ab counted twice, which is 2ab.

That little 2, the twins will tell you proudly, is not a decoration and it is not an accident. It is a headcount. It says: there are two of us. It means the exact same strip appears twice in the square. Whenever someone writes (a + b)² and forgets the 2, writing only a lonely ab, one of the twins goes missing - and Miro and Moro take that personally.

“Where’s my brother?” Miro will demand, if the middle of a square has only one strip in it.

“Right here,” Moro will say, sliding back into his side. “Count us both.”

There is a warm, satisfied feeling the twins get in the moment their strips line up and match - the small triumph of being proven, not just claimed. Anyone who has ever set two things next to each other and found them truly, exactly equal knows that feeling. It is better than being told you are right. It is showing it.

So the next time you see the middle of a square of side (a + b), look for both of them. There is Miro along the bottom. There is Moro up the side. Turn one a quarter-turn and it becomes the other, which is how you know they are twins, which is how you know the strips together are 2ab and never a single lonely ab.

“Two of the same,” says Miro, settling back into his strip.

“Means times two,” says Moro, settling into his.

And the two matching strips lie in the middle of the square, side by side and utterly equal, exactly as twins ought to be.