Dennis Walcott joined principal Annabelle Martinez (standing) and teachers at P.S. 124 in Sunset Park for training on the Common Core standards.

Huddled around tables in their school library, three dozen teachers at P.S. 124 in Sunset Park got a taste for how new standards being rolled out across the city would reshape their work in the classroom this fall.

Principal Annabelle Martinez handed out photocopies of student writing samples and asked the teachers to evaluate the work according to the new standards.

For a team of third-grade teachers, that meant looking at a short essay about weather and determining whether the author used “informative and explanatory text to examine a topic and convey ideas and information clearly.”

At first, the teachers found strengths in the essay’s display of mechanics. One teacher pointed out that the student had used capitalization correctly.

“He knows his paragraphs,” another teacher said. “And he knows sentence structure too.”

Later, the teachers used a projector to present their notes to their colleagues. Under Martinez’s guidance, the teachers revised how they discussed the student’s strengths. Now, they called the essay “informative” and said it was organized well by topic and included a “clear introduction” and a “clear conclusion” — language that was more in line with the new standards.

Scenes like this were playing out in schools across the five boroughs this morning as part of an extra day of professional development given to staff before students start class tomorrow. The training sessions were specifically targeted at preparing teachers for the citywide rollout of the Common Core curriculum standards, designed to refocus expectations to be more in line with college and career readiness.

P.S. 124 was among 100 schools that tested the core standards waters as part of a citywide pilot last year. This year, all schools are expected to begin tying instruction to the new standards, and their first step is to identify the gap between what students currently know and what the Common Core demands of them. That means teachers will be reviewing samples of student work, using the same kind of scrutiny required in today’s training exercise.

“One of the things that we strive to instill with our staff is that it’s not good enough just to teach the curriculum,” said Chief Academic Officer Shael Polakow-Suransky, who is overseeing the city’s Common Core rollout. “You can teach something and still have half the kids not learning.”

He visited P.S. 124 today along with Schools Chancellor Dennis Walcott. With the pair of top officials dropping in on the training session, teachers spoke excitedly about the new standards. But many of their comments were cut with a sense of caution.

“I feel an incredible amount of enthusiasm for the first time in eight years,” said one teacher. “I really just hope that we’re supported from the top on this.”

“We’re heading in the right direction, but there’s still fear,” another teacher remarked. “And that’s okay.”