With school starting the day after tomorrow, Miss Amy visits her second-grade classroom to make sure everything is in order. It isn’t. In the far back corner a chair and desk are missing. Miss Amy counts the desks one by one. Twenty-four. She frowns. Then she goes into the hallway and searches until she finds Mr. Gibbons, the janitor, who is pushing a broom in the gymnasium.

“Well, let us see now, Miss Amy,” Mr. Gibbons says, upon being informed of the missing chair and desk. Broom in hand, he follows Miss Amy to her classroom.

“You see, Mr. Gibbons,” says Miss Amy, her arm sweeping across the room. “Five rows of five minus one. There’s one missing.”

Mr. Gibbons nods solemnly. “Some poor child will have to stand.”

“Oh, no,” Miss Amy says. “The enrollment list shows twenty-four.”

Mr. Gibbons shakes his head. “Then what is the problem, if I may ask?”

“It’s very unnerving,” Miss Amy says. “The lack of symmetry. I’m afraid my eyes will always go to the empty space.”