At first, the little girl hung back warily, watching as medical student volunteers laid out supplies in the playroom at Johns Hopkins Children’s Center. A science-based craft project — building a small catapult from spoons, rubber bands and bottle caps — didn’t seem to draw her in. But when volunteers showed her how the tiny contraption could launch miniature pumpkins into the air, curiosity won out.

Soon, the little girl, who has cancer, was organizing teams, keeping score and becoming competitive. “She was running the show. She completely lit up the room,” says Aleksandra Drmanovic, a second-year student at the Johns Hopkins University School of Medicine who volunteers for TEACH.

Short for Together Educating All Children in Hospitals, TEACH is a national organization with chapters across the country that brings hands-on STEM learning to pediatric patients. At Johns Hopkins, the group has about a dozen board members and additional medical student volunteers who host monthly activities with patients from the Children’s Center oncology unit.

For the student volunteers — many with aspirations in pediatric medicine — seeing kids brighten during their hardest days reaffirms the path they’re on. “Hospital stays are tough for anybody, but especially for kids who want to be out there playing,” says first-year medical student Jasmine Kung, a TEACH board member. “It’s heartwarming to see them just have fun. And it works both ways — it’s a break for them and a reminder for us of why we’re doing all of this.”

The science is there, but it’s never the main point. “We sneak in science learning when we can,” says Mihir Kumar, also a first-year medical student. “It’s fun first, educational second.”

Volunteers work with child life specialists at the Children’s Center, who coordinate logistics and help identify which young patients are eligible to participate. Recent events included building battery-powered robots out of toothbrushes, making DNA necklaces and experimenting with optical illusions.

Activities are designed to be flexible, adjusting to the ages and interests of the patients, who range from about age 5 to 12. “We always have a backup plan, like coloring or word searches,” says Kung. “The space they give us is pretty awesome. There’s a basketball hoop, and sometimes we end up playing Red Light, Green Light. It just depends on what the kids want to do.”