The percentage of Montgomery County students who passed the state's standardized reading and math tests improved over last year in nearly all grades and racial and ethnic groups, according to a school system analysis of Maryland State Department of Education data.

In elementary schools, "the greatest gains we had were among the schools with the highest concentration of poverty," Superintendent Jerry D. Weast said. "You've got a closing of the gap occurring at the same time the scores went up."

The scoring for the annual Maryland School Assessment (MSA) is divided into three categories: advanced, proficient or basic. A student must score advanced or proficient to pass the test.

Since last year, the percentage of students countywide who scored advanced or proficient went up markedly among several groups, most notably in third-grade reading. For example, 40 percent of Hispanic third-graders passed the reading test in 2003 and 60 percent passed this year. Last year, 48 percent of black third-graders passed reading; this year, 64 percent did.

The share of students living in poverty and those with limited English skills who passed the tests increased in all grades in both reading and math. The percentage of third-grade special education students who passed both subjects also increased.

"I'm probably happiest that the most dramatic increase happened at Broad Acres," Weast noted. The Silver Spring elementary school's student body is nearly all poor and minority. After many reforms, 75 percent of its third-graders passed the reading test, compared to 43 percent last year.

Statewide, students improved in every group and in all subjects, results that Maryland schools Superintendent Nancy S. Grasmick called stunning. Maryland's increase in the reading pass rate for third-graders was 13 percentage points, compared with 8 percentage points in Montgomery County.

The percentage of county fifth-grade special education students who passed reading declined slightly, and eighth-grade special education students passed at lower rates than last year in both reading and math. The county pass rate failed to improve in 10th-grade reading and barely increased in eighth-grade math, areas where the rate improved statewide.

The MSA, given this spring for the second year, is used to determine whether schools pass muster under the federal No Child Left Behind Act. If scores aren't high enough or don't improve enough -- for schools as a whole and for each group of children, such as Hispanics or special education students -- schools face a variety of sanctions.

State officials have not finalized the formula for this year's performance targets, so schools will not know until later in the summer if they made the grade. The ultimate federal goal is that 100 percent of students score proficient by 2014.

MSA tests in reading are given in third, fifth, eighth and 10th grades, and math tests are given in third, fifth and eighth. A geometry test is also given to high schoolers, but results were not yet available.

Fourth-, sixth- and seventh-graders took the MSA for the first time this year, but their results, which will not count yet toward determining whether schools are making progress, were not yet available.

The percentage of Montgomery County students passing the math test decreased from 79 percent in third grade to 74 percent in fifth grade to 59 percent in eighth grade. A similar pattern held with the reading test, where the passing rate was slightly lower in the later grades. But 45 percent of 10th-graders scored advanced, according to state data -- the highest percentage of the four grades tested.

Weast said he anticipates that the number of proficient and advanced scores will increase as academic reforms are expanded into later grades. In the fall, the school system will begin discussing how to implement significant change in middle schools.

In eighth grade, 31 percent of black students and 33 percent of Hispanic students passed the math test, compared with 76 percent of whites. Meanwhile, in third grade, 63 percent of black students and 65 percent of Hispanic students passed.

In a county with a range of family incomes and language abilities, scores varied greatly by school.

At Carderock Springs Elementary School in Bethesda, for example, every third-grader passed the reading and math tests, but at other county schools, less than half the students passed, according to the state schools Web site, www.mdk12.org. At three high schools, more than nine in 10 10th-graders passed the reading test; at several other high schools, fewer than two-thirds passed.