The notice could be posted in any campus building: “iPad issues? Visit the Genius Bar in the Media Center.”

But this isn’t college. It’s Hopkins West Junior High.

Inside Kim Campbell’s seventh-grade social studies class, every student gets to keep one of the Apple tablets for the year. They use them constantly, researching class projects, reading e-books and communicating with teachers. On this day, students are using a maps app to study geography.

The iPads in Hopkins’ schools are just one edge of a digital revolution in metro-area classrooms that is changing teaching and learning as fast as the latest device is introduced. YouTube videos are replacing in-class lectures. Music applications help students learn to read music and play instruments. Teachers distribute and grade assignments digitally. Gadgets once seen as distractions are now front and center on desks as essential learning tools.

For parents, the rapid changes can be bewildering. Some skeptics argue the technologies are expensive and create a digital divide between schools that can afford them and those that cannot. Others say they are being deployed too quickly, without teachers being trained to use them.

But schools show no sign of pausing or turning back.

“The students coming to us are already digital learners,” said David Treichel, instructional technology facilitator for Minnesota’s Anoka-Hennepin school district. “It’s no longer an option to teach them in a traditional setting.”

Some say the iPad is the biggest technological innovation to hit schools since the overhead projector. A New Media Consortium report this summer described tablet computing, mobile devices and apps as the most rapidly emerging school technologies.

Millions are being allocated to outfit classrooms with the latest technology. During the 2010-2011 school year, Minnesota districts spent $100.6 million on upgrades or new technology, up from $74.4 million in 2006-07. Expensive, outdated textbooks are being replaced with devices easily updated with the latest course materials and applications.

“It motivates me to do my work because it’s a lot more fun,” said seventh-grader George Greeley. “I was more excited than usual to come back to school this year.”

He navigates his iPad like a pro, adding blue placemarks to pinpoint Great Britain, Boston and New York on a map, then helps a classmate as they trace the Mississippi and Missouri Rivers across the screen with their fingers. “You can pretty much do anything with these things,” he observed.

When Jason Szporn walks the halls of Edina High School, he sees students watching videos on their smartphones.

The teacher of advanced placement economics knows they’re not just killing time. They’re doing homework.

Along with a handful of other Minnesota teachers, Szporn has “flipped” his classroom — moving himself from the whiteboard in front of the class to the handheld devices in students’ pockets.

Szporn records and posts his lessons online for students to access at lunch, on the bus or at home. Class is spent working on difficult material together, giving teachers more one-on-one time with students.

“As teachers, we’re always looking for ways to give kids more responsibility for their own education,” Szporn said. “I could never find a way to do that until now.”

Proponents say the approach works particularly well for struggling students, who can work at their own pace, replaying the videos as needed.

Szporn and other teachers with flipped classrooms report markedly improved student test scores.

Eden Prairie, Minn., sophomore Chris Timm started a flipped algebra II course this fall. Although he isn’t struggling academically, he often misses class for cross country meets and catches up on the bus.

“I can be virtually anywhere and watch the lesson and get the same benefits as if I were in class,” he said. “So far, it’s been phenomenal for me.”

Parents with initial hesitations about too much screen time for kids also say they see potential — and necessity — in the digital changes.

When Lisa Pole of Plymouth, Minn., learned that her fourth-grade daughter would use an iPad this fall at Plymouth Creek Elementary, she had concerns.

“My first thought was, ‘Great, my kids are going to sit in class and play Angry Birds all day long.’ ”

But after seeing how easy the iPads are to use — kids become their own experts by getting answers to their questions through YouTube videos or educational apps — Pole changed her tune. Now she plans to get schooled on the iPad herself.

“Being a computer-literate citizen is one of the things my kids need when they get out of the school system,” she said. “It’s an expectation that they’ll be able to do this stuff and do it well.”