College students could take a page out of R.L. Stine’s book — it takes the author just 15 days to write 120 of them.

“It’s sort of like factory work,” Robert Lawrence Stine of “Goosebumps” fame said about writing children’s books Wednesday at a Trumbull College Master’s Tea.

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About 250 spectators — from elderly men with receding hairlines to kids not quite four feet tall — swamped Trumbull Dining Hall to hear Stine talk about his son, his books and his typing finger yesterday afternoon.

When Trumbull Master Janet Henrich introduced the author, she admitted she had been unfamiliar with Stine’s books before inviting him to Yale.

“I’m a little old for his books,” Henrich joked.

Then Stine took the stage and the audience was silent, hanging on his every move.

“You guys think I’m nostalgia, right?” he began, to audience laughter. “How would you like to be nostalgia? You wouldn’t like it. It doesn’t make you feel young.”

Stine said his writing career began when he was nine, when he would write joke books and short stories on his home typewriter. Back then, his literary heroes were science fiction writers like Ray Bradbury and Isaac Asimov, he said.

Flash forward five decades and not all that much has changed. Stine still types his books as he did when he was nine — with one finger.

“I have written 300 books with this finger,” he said, showing the index finger of his left hand. “Look at it! It’s ruined! It’s totally curved!”

After graduating from Ohio State University, Stine started writing professionally, working in educational magazines with Scholastic publishing company. Soon after, in 1986, he was approached by an editor to write his first horror book, “Blind Date.”

Not much later, he started his first series, called “Fear Street,” which places teenagers in supernatural and horror situations. In many of the books in the series, teenagers are maimed or killed.

“I don’t know why I enjoyed killing teenagers so much,” he pondered aloud. “Then I realized I have one at home. Probably that’s why I liked it.”

Stine continued to talk about his son — and his literary habits. Matthew read Garfield and Calvin and Hobbes comic books, Stine said, but never his father’s books.

Still, Stine said Matthew profited from his father’s popular series Goosebumps.

In school, Matthew sold rights for his classmates’ names to be published in upcoming Goosebumps books, Stine explained. Matthew would make $10 for each sale. And at home, Matthew would ask his dad to follow through with the plan.

“Of course I always did it,” he admitted.

He ended his presentation with a look back at his successes — including three Nickelodeon Kids’ Choice Awards and a Goosebumps-themed amusement park attraction at Disney World.

“No one knows how these things happen,” he said of his literary success among children. “It’s a secret kids network — kids telling kids. There was no advertising, no hype.”

During the question-and-answer section, students both prodded Stine to explain his motivations for writing and quizzed him on Goosebumps trivia.

But others tried a different approach: to wheedle their way into children’s horror fame.

“Can you use ‘Stan’ in book 12?” asked a Yale student, referencing Stine’s new 12-book Goosebumps series, which he began this year.

Stine replied, “Do you have $10?”

At the end of Stine’s prepared presentation and before the question-and-answer section, several members of the Pundits society staged a public joke in the center of the dining hall. As one guy took out a camera and screamed, “I got a camera!” other members of the group got up around the dining hall and pleaded for the cameraman to desist, as if the camera were a gun. When the man took a fake photograph of one of the Pundits, the Pundit acted as if he were in pain and said, “Oh no, I sprained my ankle.” Another Pundit with fake blood smeared all over his neck and T-shirt started to scream. And as suddenly as the joke began, the Pundits ran out of the dining hall.

Stine was shocked.

“Does this happen at every tea?” the author asked. “That was terrifying.”

Many students said they would sit through the Tea all over again — because Stine was so captivating.

“He was the most seminal figure in my life,” Ellis Ludwig-Leone ’11 said. “Ever.”

After the tea, dozens crowded around him asking for photographs and autographs.

At the end of the queue, Henrich presented a copy of a book in the Goosebumps series for Stine to autograph. He signed it on the top of the first page. And after Stine returned to his Upper West Side apartment Wednesday night, the book was returned to the stacks of Sterling Memorial Library.