Teaching kids takes so much effort, staffers at John Dewey High School in Brooklyn have found a quicker way to fix persistent failure rates, sources said: Just let them pass.

Investigators are probing accusations of a massive grade-fixing scheme by educators desperate to boost the graduation rate at Dewey, The Post has learned.

Multiple sources claim Dewey is cutting corners by passing kids with the help of a shady “credit recovery” program that students sarcastically call “Easy Pass.”

The system allows failing pupils to get passing grades by playing games, doing work online or taking abbreviated programs that critics argue lack academic rigor.

In one alleged grade-booster, kids got science credit for watching “Jurassic Park,” sources said.

“It’s a bogus way of improving the graduation rate,” said Martin Haber, the former teachers union rep at Dewey and a retired special education teacher.

“The teachers have been under heavy pressure by their assistant principals to pass as many students as possible,” he added.

Among the accusations against Dewey is that teachers who are licensed in one subject, such as English, were passing kids for recovery programs in math, a violation under state education law.

Sources also claim make-up “academy” programs were set up during winter and spring breaks when kids were awarded credit for doing little work.

“Kids who saw the movie ‘Jurassic Park’ were given credit for their Living Environment course,” an insider said.

Other students were given a packet of work to complete in the computer room, but actually played games instead.

There were also blended “Project Graduation” courses, where kids were given an opportunity to earn credit for a variety of subjects. But teachers were stunned when students who failed to pass those courses ended up on the graduation rolls anyway after assistant principals and department heads changed their grades, sources said.

“It’s academic fraud,” a Dewey insider said.

Teachers and principals face strong penalties if their schools fail too many students. Top administrators could be fired or reassigned; and during the Bloomberg administration, when the “Easy Pass” system allegedly began, failing schools could be closed.

On the other hand, administrators who meet graduation goals can get cash bonuses.

The chancellor’s Office of Special Investigations interviewed Dewey teachers and administrators last fall, sources said.

The city Department of Education confirmed the ongoing probe, but declined to elaborate.

Dewey’s graduation rate has improved significantly under the four-year tenure of Principal Kathleen Elvin. In 2009, Dewey’s graduation rate was 56 percent, according to the state Education Department. By last year, the rate had steadily climbed to 74 percent, state data show.

The city’s own figures — which include students who graduate over the summer — reported Dewey’s graduation rate increased seven points since 2012, to 79 percent from 72 percent.

Elvin did not return requests for comment. The probe has staffers on edge.

“This is a major investigation,” an insider said. “This involves a large number of staffers and student grades.”