Only half of students who graduated from Prince George’s County’s public high schools last year enrolled in college, and 90 percent of the graduates in community college are taking remedial classes in math and reading, according to data shared with the county’s Board of Education on Thursday during a presentation on student achievement, secondary-school changes and the new academic standards.

In the 2012-13 school year, more than a fifth of the county’s freshmen had to repeat ninth grade, the data showed, and 40 percent of second-graders did not read at or above grade level.

“College and career readiness is built on a foundation that goes all the way back to pre-kindergarten,” said A. Duane Arbogast, the chief academic officer, told the board.

After Arbogast’s presentation, board members spent more than an hour asking about professional development for teachers, parental engagement and the implementation of Common Core, a new national curriculum being implemented in most states.

Thursday’s meeting was one of the first sessions to focus largely on student achievement since the board’s reconfiguration under a state law that took effect in June. The board’s powers are limited to improving academic achievement and increasing parental and community engagement.

Several board members raised concerns about what is being done to raise achievement, especially as the county continues to roll out the Common Core standards.

“I’m not hearing a concrete plan to make sure we are not leaving kids behind,” said Vice Chairman Carolyn M. Boston (District 6). “I’m concerned that we might.”

Arbogast said the county has redeployed reading specialists in low-performing schools. The same will be done with math specialists, he said.

Deputy Superintendent Monique Davis said that in the past six weeks, officials have been monitoring the work of at-risk ninth-graders and discussing solutions with elementary, middle and high school principals. She said 23 percent of freshmen are on the verge of failing English class.

Board member Verjeana M. Jacobs (District 5) asked for assurances that professional development is “happening in a meaningful way.”

Arbogast said he regretted that he didn’t have a positive response.

“The public school calendar in Prince George’s and most places is not as supportive of professional development as we’d like,” he said. “That’s a challenge for us.”

Board member Patricia Eubanks (District 4) said a major obstacle is figuring out how to get parents involved. “That is going to be a problem — getting the parents engaged at the dinner table,” she said. Many parents are afraid to help with homework, she said, because of an unfamiliarity with the material.

Arbogast said that although the school system has its challenges, it also provides a rigorous curriculum and numerous speciality offerings, such as its Science, Technology, Engineering and Mathematics (STEM), Talented and Gifted (TAG) and International Baccalaureate programs.

Schools chief Kevin Maxwell has indicated that he wants to expand some of those speciality programs, including offering IB courses in elementary school.

“We have some very successful programs,” Arbogast said. “Dr. Maxwell wants to expand these to all kids.”