To Garnet Valley High School social studies teacher Christine Gumpert, the biggest waste in her Non-Western Cultures class is the $100 the district shells out for each bulky textbook that covers, at best, 10 percent of the curriculum and is out-of-date the minute it rolls off the presses.

Next year, though, when Gumpert's ninth graders reach into their backpacks, they will pull out slim laptops instead of overweight tomes and use mostly free online resources, including the latest current events from Africa, the Middle East, and anywhere else on Earth.

Garnet Valley is one of a handful of Philadelphia-area districts, and three in northern New Jersey, that are in the vanguard of a nationwide movement to ditch traditional textbooks for open-source educational resources on the web. Along with budget savings, which can reach hundreds of thousands of dollars in a district, proponents say it gives teachers more freedom to custom-tailor curriculums and allows students to learn where they're already most comfortable -- on computers.

"What we are doing is having ownership of what we do in the classroom, which, frankly, in education is a dwindling right," said Gumpert, who has become an enthusiastic evangelist, as have administrators in her Delaware County district. They already are looking beyond social studies to target other courses of study to reduce their annual textbook outlay, which two years ago was $400,000.

Garnet Valley, Upper Perkiomen in Montgomery County, Downingtown Area in Chester County, and Centennial in Bucks are pioneering members in the U.S. Department of Education's 2015 #GoOpen initiative, which aims to expand the amount of open-license learning materials on the internet and help train teachers on how to best use them.

Upper Perkiomen began exploring the concept even before #GoOpen was launched and has been named an "ambassador school" to help promote and expand the federal program. Officials there say that English classes in grades six through 12, as well as ninth grade Integrated Science already are textbook-free, while the district experiments with taking other subjects either all or mostly online.

"It works, but it doesn't work everywhere in my opinion," said Upper Perkiomen Superintendent Alexis McGloin, who attended a #GoOpen promotional event at the Obama White House.

Elementary teachers who wanted to take math digital four years ago, McGloin explained, struggled to find the right materials online and eventually ordered some textbooks – the kind of problem that #GoOpen is working to solve.

Other issues must be resolved as curriculums move increasingly online. These include the need to provide every student with a laptop, and to extensively train teachers how to find and curate the best digital learning sources.

"Getting teachers ready to write with open education resources takes two years of training," said Anthony Gabriel, a curriculum supervisor in Garnet Valley, which required all students to use a device such as a laptop or iPad this year. "It's not just like, 'Let me go out and Google some articles.' It takes a year of setup and a year where they're writing with consistent training."

The money saved on books, he said, will go to pay teachers to develop curriculums and to teach them how to use the new resources.

While some parents might grumble about suddenly lighter backpacks, students are usually enthusiastic about learning on a computer, where their generation feels more at home than cracking open a book.

Garnet Valley senior Bethany Hofmann, 18, said that for the first three years of high school she used texts and paper notebooks in class. This year, the district required students to use a device such as a laptop or iPad, opening the door to a learning experience that is "more applicable to real life scenarios, like when I go to college," she said "It's really, really helpful."

School administrators say one of the things they like most about open online learning is the chance to save money in a time of declining government aid and relentless budget crunches. Textbooks are now their biggest curriculum cost.

At Centennial, A.J. Juliani, the new director of technology and innovation, is launching the district's digital program after he did the same for his former employer, Upper Perkiomen. The latter saved about $200,000 on textbooks and related curriculum costs and plowed some of that money back into new learning initiatives.

Juliani said that Centennial is looking at ways to use #GoOpen and other online materials, as well as academic partnerships to expand its curriculums. He cited a free SAT prep course that has been added at William Tennent High School in Warminster, and a high school Genetics of Cancer course developed in partnership with Fox Chase Cancer Center and St. Joseph's University that uses open educational resources.

"We're just kind of starting the journey," Juliani said. "Only a couple months into it, you can already see the mind-set shift. Now when people are planning curriculum, they are already talking about how the learning should look, not what the resource" – usually a textbook – "looks like." The pace of change will pick up, he said, after a new round of teacher training this summer.

Marc Bertrando, superintendent of Garnet Valley, said he predicts the number of local districts swapping textbooks for digital learning will grow exponentially as more schools post their learning materials online.

"If we develop our own U.S. history open educational resource, why couldn't we share that with West Chester, and if West Chester builds an English open educational resource, why can't they reach out to us?" asked Bertrando, adding that he hopes his district will be textbook-free in five to 10 years.

Still, most schools find it difficult to move quickly and completely to free online sources, so class work is still often blended with paid materials, such as the novels that Upper Perkiomen students read in English classes.

"The emphasis is looking at present issues in the world," she said. "There's not a good history textbook for that. Once a book comes off the presses, it is almost obsolete when teaching current  issues. When this open educational resource idea was brought to us, we were like, 'Yeah, this fits.' "