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Unless you’ve spent time in a high school classroom recently, you’ve probably never seen a “Crash Course” video.

These irreverent and fast-paced educational clips tackle a variety of topics, such as the 13.8 billion-year history of the universe, or the fading American Dream as depicted by F. Scott Fitzgerald in his Jazz Age novel, “The Great Gatsby.” All in about 10 minutes.

“Crash Course” videos, which have attracted 2.4 million YouTube subscribers, are about to get a larger audience through a partnership with PBS Digital Studios.

Creators John and Hank Green — known as the Vlogbrothers — agreed to distribute their educational video library through PBS’s YouTube network as well as into the classroom through PBS LearningMedia, an on-demand digital service that’s free to educators nationwide. The videos become available in January.

“Being able to reach people we haven’t been able to reach before — in many cases, it’s in the schools that need the most resources — is wonderful for us,” said Hank Green. “Having a legitimate way to broadcast into schools, that doesn’t include advertising, is really great.”

Hank and John Green are among a growing number of YouTube personalities to join the entertainment mainstream. John Green is also the best-selling young adult novelist, whose “The Fault in Our Stars” was turned into one of the highest-grossing films this summer. And Hank Green is chief executive of VidCon, a sprawling convention (in which his brother is involved) that showcases YouTube stars. Last year’s attracted 18,000 attendees.

Under the PBS agreement, “Crash Course” will launch two new series, one on U.S. government, to be hosted by YouTube personality Craig Benzine, also known as WheezyWaiter, and the other on astronomy, featuring astronomer and the author of Slate’s “Bad Astronomy” blog Phil Plait.

“We’re always looking to work with the best and the brightest,” said PBS Digital General Manager Ira Rubenstein, adding that through the partnership, “We gain great quality content.”

The “Crash Course” videos debuted in 2011 as part of YouTube’s original content initiative to underwrite 100 new channels. But after two years of financing, YouTube cut the cord. Hank and John had to search for alternative backing.

They solicited donations through Subbable, a subscription service they launched to coax viewers to contribute to their favorite channels and collect perquisites. It also received a funding from bgC3, a think tank created by Microsoft founder Bill Gates. The partnership with PBS, though, is a “substantially larger” source of revenue than either of those other funding sources, Hank Green said.

“It means we can create twice as much content, which is amazing,” he said. “We’re doubling the number of videos that will go on our channels, we’re doubling the number of courses we can do in a year.”

Eventually, the Greens hope to produce “Crash Course” videos to span the high school curriculum — offering a 10-minute introduction (or review) of world history, chemistry, psychology, literature and more. All done in a staccato style that’s designed to hold the young viewer’s attention.

“We’re making content for young people who are in the most distractible environment of all time,” Hank Green said. “We have to be entertaining.”

For the uninitiated, here’s a sample “Crash Course” video:

Updated at 9:50 a.m. The story originally reported that Crash Course videos received a grant from the Bill & Melinda Gates Foundation. It received backing from a Gates think tank, bcC3.