"The kids are able to explain the material, and when they can do that, that's when they really get it," Kliewer says. "Sometimes it doesn't click when I do it." And opportunities for reinforcement are ever present. Students can take the phones home with them, so they're able to ask Kliewer or their classmates questions about math concepts virtually 24/7. "The connectivity has been the critical element," says Gross. "The device allows them to continue to use instructional resources when they're on the school bus or waiting for a parent at work. If they have a specific question, they always have access to an expert, whether it's a student peer or a tutor."