“Larry, sit on your tushie! If it’s going to be tough for you to sit on your bottom,” Mrs. Keenan chides, “you’re going to have to leave the circle!”

Summers sits up, startled—until a glance around the room reveals that Mrs. Keenan’s warning was meant for another, smaller Larry (first grade is confusing for Harvard presidents, too).

The student beside him stops squirming, and Summers breathes a sigh of relief.

“Break time,” Mrs. Keenan says. “Time to get your wiggles out!”

The students stand up, gyrating their hips back and forth. “Touch the stars! Touch the ground, touch your toes!” Mrs. Keenan commands, as the kids reach up and then down, jiggling all their limbs about.

But as little Larry shakes his tushie, Summers remains grounded—after all, even if you’re principal for a day, you can’t wiggle your way out of the responsibilities required of a Harvard president.

Summers and his like-named neighbor pair off for the “Towers of 10” game.

As they take turns rolling dice and building “towers” of blocks from the results, a crowd of five other first-grade teachers looks on as part of a school program that fosters discussions of lesson plans and their efficacy.

“I know Larry Summers has been paying attention,” says the school’s real-life principal, Joanne Russell, who is also observing the class.

Summers looks at home, playing with blocks and using crayons to record their results, but his frame looks a little large for the child-sized wooden chair.

Afterwards, Summers meets with Keenan and the other first-grade teachers to discuss the class.

He asks about the students’ backgrounds.

“Some were very able to get themselves into the concept [of counting] right away,” Summers observes. “But others couldn’t.”

“What percentage of these students have parents at home who read to them, who give them dinner at a relatively stable time?” he asks.

Keenan estimates less than half; Russell less than 40 percent.