Once forbidden, students in more than 2,000 school districts across the country are now learning with electronic devices.  

Students can use tablets — whether from Apple or rival brands — to take notes, submit assignments and engage in group discussions with teachers or other students.

While this revolution raises concerns about cost and effectiveness, schools and textbook publishers say it's opened up a new chapter in education, changing the way students interact with teachers and with one another.

"Teachers are having to rethink their classroom," said Becky Keith, a technology integration specialist at Woodford County Public Schools in Kentucky. "The teachers who are embracing it are having great success."

Teachers in digital classrooms have become learning coaches, moving around the room and giving students more one-on-one instruction. Educators who have embraced this approach said it better prepares students for the interactive environments they'll encounter in their college and professional lives.