FILE (Juana Arias/TWP)

D.C. Public Schools announced Thursday that it has purchased 85,000 new books for school libraries around the city, an investment that comes after years of pressure from parents and activists.

Schools also have received 4,000 new musical instruments, 2,000 desktop computers and more than 1,300 laptops and tablets, as well as art supplies and science lab equipment.

The new materials cost a total of about $10 million, money left unspent because of unfilled personnel vacancies and reduced benefits costs, officials said.

“When we realized these funds would be available, we came up with a thoughtful and strategic plan to make purchases that would both help our students learn and achieve, and support our teachers with new, modern equipment and supplies,” Schools Chancellor Kaya Henderson said in a statement. “The action at DCPS is in the classroom, and that’s where we’re putting our resources.”

Several renovated and rebuilt schools, which opened with brand-new libraries but very few books, received full collections. They included Anacostia High School, Kramer Middle School and the McKinley and Cardozo Education campuses.

But every school in the city received some new books, and the infusion of current titles came as a thrill to librarians who are used to holding book sales and soliciting donations in order to improve aging collections.

“It’s wonderful,” said Currie Renwick, the librarian at Watkins Elementary on Capitol Hill, which received more than 200 fiction and nonfiction titles. “We’re just so pleased. . . . For many children, there are not books at home, so it’s critical we have the best books that we can get.”

Renwick said that before the new books arrived in November, the average copyright date in the Watkins library was around 1994, a vintage that is “unacceptable,” she said. Science books, in particular, need refreshing more often, she said.

“You know the phrase, ‘You can’t judge a book by its cover’? That is true to some extent, but you certainly can judge a nonfiction book by its copyright date,” said Renwick. “And with fiction, you have to have fresh material.”

Renwick said she’s hopeful that in the future, the school system will make a practice of earmarking money in the budget for library materials.

Peter MacPherson, a parent who has long pushed for more investment in and attention to school libraries, also said the libraries will need a regular influx of dollars in order to update their collections. But this infusion of books is “a fabulous development,” he said.

“The work is not done, but it’s a great, great first step.”

The school system is considering the possibility of budgeting for regular updates of library materials, said spokeswoman Melissa Salmanowitz.