Vishnu Sanigepalli was a senior at Brooklyn Technical High School when his calculus class was struggling to visualize the solid at the point where two cylinders intersect. (See? It’s tough to visualize.)

Sanigepalli decided to 3-D print a model to help him and his peers better understand what this intersection looked like. “Before, it was just in my mind, or on a piece of paper or on a computer,” Sanigepalli explained in a MakerBot video. “That wasn’t as cool as having the project in your hand because you’re able to touch it.”

The stories about the amazing things created with 3-D printers just keep coming: a trachea for a newborn baby struggling to breathe on his own, an (adorable) webbed foot for a duck, an entire working car. But as much as 3-D printing has revolutionized rapid prototyping and manufacturing, it’s turning out to be a game changer for teaching and learning. As kids like Sanigepalli watch their creations come to life, layer by miniscule layer, they’re picking up critical STEM skills that equip them for the 21st-century economy.

“The new era of rapid prototyping and the vast accessibility is opening up the field of engineering as a whole,” said Tom Curanovic, senior mechanical engineering instructor at Brooklyn Tech. “We’re seeing a lot more interest from all sorts of students, starting as early as freshman year.”

Brooklyn Tech is using 3-D printers in a required class, “Design and Drawing for Production,” but in schools around the country, educators are using this technology across the curricular spectrum.

You can get a sense of the demand by looking at DonorsChoose, which is only one site where teachers crowd fund their printers when there’s no room in the school’s budget. A New York classroom is looking for a printer for a course called “Art for Engineers.” A teacher in San Jose wants her students to print models of microscopic organisms. And a classroom in Highland Park, Illinois, needs filament spools to print inventions they’ve designed in programs such as SketchUp and Autodesk Inventor.

Accessible 3-D printers are only one type of technology spurring the growing maker movement in Pittsburgh and its classrooms.

“There is an explosion of maker activity in our city,” wrote Mayor Bill Peduto and co-authors Gregg Behr and Subra Suresh in the Pittsburgh Post-Gazette last month. Behr is executive director of the Grable Foundation and Suresh is president of Carnegie Mellon University. The authors highlighted places around the city like AlphaLab Gear and HackPittsburgh where people can make and innovate in their very own neighborhoods. “Digital technology—such as apps and other software, games and robots, some of them invented right here—is opening new pathways for many more people to make and test new ideas, and to build new jobs and the city’s economy right along with them,” they wrote.

In 2011, the Department of Commerce found that growth in STEM jobs, like the ones Peduto praised, was three times faster than growth in non-STEM jobs in the last decade. And, as a Brookings report found, 20 percent of Department of Commerce jobs in the United States in 2011 required a high level of knowledge in any one STEM field.

Christine Mytko, a science teacher at Black Pine Circle School in Berkeley, California, hosts a blog—Tales of a 3D Printer—detailing the ways she’s engaged kids in STEM fields. For the schools’ graduation last year, each student printed an artifact they wanted to remember from their middle school days. Perhaps most telling was the student who 3-D printed a 3-D printer, explaining that he’s not giving up on 3-D printing his iPad stand. (He later updated the post to say he figured it out.)

Last month, SpaceX and NASA sent a zero-gravity 3-D printer up to the international space station. Yep, you read that right. Astronauts will soon be able to 3-D print in zero gravity to create extra parts and tools. It’s the kind of little news item that makes predicting the future of technology feel utterly impossible. But it seems educators and students agree on one thing—the printing won’t be in 2-D.