Members of the public grilled the mayor on crowded classes and school discipline during a two-hour-plus education forum Thursday night.

The public event at P.S. 69 in Jackson Heights was Mayor Bill de Blasio’s second-ever town hall meeting and the first focused on public schools. Questions from the Queens-heavy crowd centered on topics with a direct impact on local students and educators, from jam-packed schools to high-stakes tests and English classes for immigrant parents.

In contrast, the mayor faced relatively few questions about policy debates that have flared up in New York and across the country: how to turn around struggling schools, promote school diversity, and evaluate teachers. While the strict discipline policies at Success Academy and other charter schools have grabbed headlines and prompted press conferences in recent days, the crowd in Queens — where charters are relatively rare — did not mention them Thursday.

Before the forum, some critics had seized on City Hall’s requirement that would-be attendees reserve spots through Queens City Councilman Daniel Dromm. The pro-charter advocacy group Families for Excellent Schools called it a “Potemkin Town Hall.”

Standing in one of the city’s most crowded districts, de Blasio fielded a number of questions about class size. The district is so tight on space that it will still be short 900 seats even after new schools open, according to the city’s Independent Budget Office. Citywide, about 44 percent of city students attended overcrowded schools in 2013-14, according to the IBO.

The issue is a top concern for parents and was a problem de Blasio promised to address during his campaign for mayor, critics pointed out at the forum.

De Blasio responded that his hands are tied by funding. He will invest $3.5 million to increase capacity throughout the city and another $500 million to remove school trailers, but these funds are not sufficient, he said.

“It’s 4 billion dollars and it’s not enough. I’m very comfortable telling you here in public that it’s not enough,” he said.

De Blasio also answered several questions about police presence in schools and the impact of harsh disciplinary policies on students.

Suspensions fell by 17 percent last year, progress that the mayor promised last month to build on. Yet for some, this is not enough.

An advocate asked whether de Blasio would put school safety officers back under the control of the education department instead of the police, which advocates argue can lead to the criminalization of student misbehavior. The mayor said he supports police oversight and added, in a rare display of praise for his predecessor, that he thought former Mayor Michael Bloomberg’s school discipline policies had led to “real progress.”

Even as school suspensions have sharply declined, black and Hispanic students continue to face harsher punishments at a disproportionate rate. But when pushed about the impact of disciplinary policies on students of color, de Blasio said he is trying to find a middle ground between keeping schools safe and eliminating racial disparities in discipline.

“I’ve got to be straight up about the fact that we are balancing real safety needs in the school,” de Blasio said

In response to complaints about the state’s standardized exams, de Blasio said he felt “kindred” with the opt-out movement, which grew to include 7,900 city students this year but remains greatly overshadowed by the state-wide boycotts. He also touted his administration’s shift away from using test scores to evaluate schools.

But one middle school teacher took the microphone to say the changes have made little difference.

“I know that you’ve spoken about the reduced focus on testing but I want you to know that I’m really not seeing it,” Amanda Vender said.

After the forum, parents who attended  had mixed views on de Blasio’s answers.

Ron Hayduk, a parent at P.S. 69, called the meeting an “honest exchange” with “substantive questions.

Another parent, Dudley Stewart, had a different take.

“[The mayor] didn’t quite have answers for a couple of the important things that people brought up,” Stewart said.