James Tierinni has seen what happens when schools ban phones. “About eight, nine years ago, I had to police people’s cellphones. And I’d have to talk to the same kid over and over again,” Tierinni said. Now, when he gives out a class exercise, “they turn their desks, they talk to each other … and it’s generally just so much more of a positive environment.” Tierinni teaches math in Manchester. The district became an early adopter of a bell-to-bell cellphone ban across all schools a few years ago.