They explore the old Boeing 727 plane as any group of students on a museum field trip might. But when told that the plane weighs 165,000 pounds - or about as much as 10 elephants - several children give knowing nods.
"Ohhh," a first-grader says. "We have 10 elephants at home."
If life for them sounds like a bit of a circus, it is - the Ringling Bros. and Barnum & Bailey circus. They are the children of acrobats, trapeze artists, animal keepers, and others who travel the country nearly year round with their families in tow.
For the kids, life on the road can be an education in itself. They get to visit sites many students only read about, from Bunker Hill to the US Mint to, in this case, Chicago's Museum of Science and Industry. It's one of the advantages of their journey by train, truck, and trailer with a circus that has been described as the largest city without a ZIP code.
But the school in this town more often comes in the form of a teacher who travels with them, providing a steady routine of homework and tests even as the scenery changes.
It's not the most glamorous side of the "Greatest Show on Earth." School accommodations are often cramped.
In Chicago, it's a small, L-shaped dressing room at the United Center, which hosts the circus and other shows when the city's professional basketball and hockey teams aren't playing. The windowless room only has space for a few tables, folding chairs, and a large wooden box on rollers that carries the school's supplies from place to place.
Yet Brenda Shaw, teacher for the Ringling Bros., has done her best to brighten the room's walls with student artwork and strings of leaves cut out of red, orange, and yellow construction paper.
The students attend class on any day the circus has shows scheduled. So that means they often go six - and even sometimes seven - days a week.
While watching TV, walking dogs (allowed for those who have their own trailers), and playing games with one another rank high on the students' lists, much of their time is spent on schoolwork.
Some parents with Ringling Bros. see the arrangement as a trade-off when compared with traditional school. Carrie Valentin has put her 6-year-old daughter, Lexie, in both Ms. Shaw's class and an Indianapolis elementary school during the off-season.
"I do feel bad about that these kids don't get a chance to run around much - like at recess," says Ms. Valentin, who works in the show's day care department. But she says Lexie also gets individual attention from Shaw that she could never get in a classroom of 30 children.