Prince George's County students posted higher scores on Maryland's reading and math tests since last year, mirroring an overall improvement across the state on the two-year-old high-stakes exam.

The percentage of county public students passing the reading and math Maryland School Assessments increased in grades 3, 5 and 8, according to results released Tuesday by the Maryland State Department of Education. Tenth-grade reading scores also went up.

While the scores of Prince George's students still lagged behind statewide averages, the county's schools chief said he was proud of the progress made and looked forward to more.

Third-graders in Prince George's had the largest overall increase among all the grade levels: a 15.9-percentage-point spike in reading.

Scores are deemed basic, proficient or advanced, but students must earn at least a proficient score to pass the test.

This is the second year that Maryland students in grades 3, 5, 8 and 10 have taken the tests, which were administered this spring. Students in grades 4, 6 and 7 took the exams for the first time this year. Those results -- as well as those for 10th-graders who took the math test -- will not be released until the end of the summer because state officials have not yet determined passing scores.

Statewide, scores increased in both reading and math. Most significant was the jump on the third-grade reading test: Seventy-one percent of students in the state passed that exam, up nearly 13 percent from last year.

Compared with statewide averages, Prince George's students were behind, a trend that has persisted for many years through different testing systems used by the state. County students often are outperformed by their peers elsewhere in Maryland, and frequently find themselves second from the bottom in statewide testing, ahead of only Baltimore.

No data are available yet to assess how the county performed compared with other jurisdictions. But Prince George's school officials said the gap between the county's scores and the state average has decreased.

"How far away was I from the statewide average last year?" said schools chief Andre J. Hornsby in an interview Tuesday. "You can't fix this in one year, but if you go about it in the right manner, growth is what I expect."

Hornsby, who took over the school system a year ago, credited his emphasis on improving reading instruction for the gains. This year, he required teachers to go through a training program to learn how to teach reading. He has also made teachers regularly assess students to see how they were progressing throughout the year.

"I have focused on reading since the day I walked in," he said.

But Hornsby also made several administrative changes that he said went a long way toward improving academics at some of the district's lowest-performing schools. Last summer, a week before school was scheduled to start, Hornsby reassigned nine principals because they had not brought about enough academic progress. Hornsby handpicked their replacements. Some of the schools that received new principals were on Maryland's watch list, at risk of state takeover.

"My attitude with principals was simple: [Having] no improvement is unacceptable," he said.

According to figures from the State Department of Education, at Arrowhead Elementary School in Upper Marlboro, 46.3 percent of third-graders scored proficient on the reading exam, compared with 24.5 percent the year before. The percentage of fifth-graders scoring proficient in reading was 47.3, up from 26.8 the previous year. Of those passing the test, 16.1 percent were rated advanced, meaning that they exceeded proficiency levels. And at Nicholas Orem Middle School in Hyattsville, 45.6 percent of eighth-graders were proficient in reading, up from 28.5 the previous year.

The results will be used to determine which schools are on the right track and which are "in need of improvement" under the federal No Child Left Behind Act. State officials said they cannot yet calculate which schools met what is called "adequate yearly progress" because the U.S. Department of Education has not approved the formula the state will use to calculate it.

The law also requires states to analyze performance based on race, income, the student's ability to speak English and enrollment in special education programs. If any one of the groups fails, the entire school fails. Schools that do not meet benchmarks eventually could face state takeover.

All students must be proficient in reading and math by 2014.

The minority achievement gap persisted in Prince George's, but scores among African American and Hispanic students rose in all grade levels in reading and math. Those students considered to be living in poverty, those in special education and those speaking limited English had increases on both tests in almost every grade level.

At Mary Harris "Mother" Jones Elementary School in Adelphi, for example, state figures show 37.3 percent of third-graders labeled limited English proficient scored proficient in reading, up from 3.8 percent the year before. Forty-two percent of fifth-graders in that category were proficient in reading, compared with just under 10 percent last year.

"It's such a validation. It's just awesome," said Principal Cheryl Logan. "I'm just so proud of the kids."

Hornsby said he is optimistic about the future.

"I think what we're going to find is that many of our schools are going to make [adequate yearly progress]," the federal standard, he said. "It's only going to get better from here."

To see state test results for individual schools and counties, visit www.mdreportcard.org.