Schools put limits on students using cellphones. Tablets might be next.

The assignment for Kathryn Perrotta’s fourth-graders was to learn about density by building a “neutral buoyancy” contraption that wouldn’t sink or float.

The St. Paul summer school students turned to their iPads and an app where they had drafted plans the day before. Then they ditched the screens for a bin full of materials, including balloons, straws, marbles and popsicle sticks, and worked with their peers to bring their plans to life.

That practice — look online to learn, then reinforce a lesson with hands-on, off-screen activities — is intentional, and one Perrotta comes back to with most of her lessons at Frost Lake Elementary.

“I want parents to know that screen time in the classroom is not passive,” Perrotta said. “It’s something that is purposeful, closely monitored and balanced.”

The pandemic forced educators and families to embrace technology in learning, and most Minnesota school districts now provide a tablet or laptop for each child. But amid broader cultural concerns about screen time and its impact on kids’ attention spans and mental health, parents and teachers are asking more questions about moderation for in-class devices, especially for younger students.

Schools statewide have already had to reckon with cellphones after the Legislature in 2024 required districts to develop policies about phone use in class. The next push, education leaders say, could be for additional guidance or structure on how — or how long — devices are used in class.

“I feel like during COVID, everyone just kind of said, ‘Go for it,’ when it came to tech in education,” said Marguerite Ohrtman, the director of school counseling at the University of Minnesota. “We didn’t know what that impact was, and now we have people going, ‘Oh wait, is this addictive? Is there long-term harm?’ ”

That left ambiguity about the amount of time students, especially those older than kindergarten age, should spend on screens in class.

John Horton, a teacher at J.J. Hill Montessori in St. Paul, makes it a priority to discuss responsible technology use with his students and their parents. His second-grade students are limited to 25 minutes of classroom screen time a day; older grades can have longer if using an iPad for research.

Most students know the routine, but some still have a hard time handing over the device, he said.

“We talk about how some technology is designed to pull your attention,” Horton said, adding that he prompts his students to think about whether time on their devices are helping them learn.

“There’s definitely a place for technology in the classroom,” he said. ”But it has to be carefully taught and mindfully curated, and I’m not sure we are always doing a great job of that yet."

That’s why she’s considering a private school that doesn’t provide students with devices until middle school.

“I think we are all just doing the best with what we have and trying to raise our kids to be safe, healthy and happy,” she said.

Communicating to parents about screens in the classroom is, ironically, made easier by online learning platforms, said Phil Boyd, a kindergarten teacher at R.L. Stevenson Elementary in Fridley.

Before the year starts, Boyd explains to parents his philosophy on tech in the classroom: He uses it when it enhances learning, and only in small groups that rotate through activities. An individual student likely gets just 20 minutes on a computer once or twice a week.

Teachers design lessons around learning goals, which sometimes include helping students develop technological skills, Boyd said.

Shannon Skibba, a second-grade teacher in the Fridley district, also includes technology in rotations, which offers variety and allows her to monitor the students on screens. She’s noticed that students are usually more excited for the hands-on activities than the ones on a device, though it depends on the kid and how much screen time they get at home.

“Most of the feedback they give me is they actually want that balance,” she said. “But they do ask for more video games.”

In Perrotta’s summer school classroom in St. Paul, students’ iPad screens went dark on their desks as they worked to craft their science projects with marbles, twine and plastic foam.

Student Merida Auld said she enjoyed designing her idea on the iPad, which she sees as “helpful for learning.”

“But we are good at making sure not to do too much on it so we don’t get addicted,” she said. “We always talk about that in class.”