Second-graders in Montgomery County's poorest communities continued to show gains on a national exam, according to data the school system will release today.

Scores on the 2004 Comprehensive Test of Basic Skills increased in three categories -- including language and math -- in the 17 county schools that were the first to receive smaller classes and intensive academic services, the data show. In two other categories, scores held steady this year after rising in 2003.

The 17 elementary schools are east of Interstate 270, mostly in Silver Spring and Rockville. Because of their high-poverty student populations, they were selected by Superintendent Jerry D. Weast to be the focus of improvement efforts that began four years ago. The efforts included concentration on reading and math, more training for teachers, many assessments throughout the year and a new curriculum.

In those schools, where children through third grade have experienced the programs each year, CTBS scores have increased significantly in all subjects since 2000, officials said. Test categories are reading, language, language mechanics, math and math computation.

Weast said in an interview that the results show that "a good curriculum in the hands of a well-trained teacher who is given clear expectations that are high can make a huge difference in the life of a child."

"As these kids roll up" through the grades, he said, "they're going to be able to do higher and higher work."

The county's overall scores on the CTBS, a multiple-choice test given to second-graders in March, improved in most subjects from last year. The CTBS is no longer required of Maryland schools -- statewide standardized testing now begins in third grade -- but Montgomery County is using the test to measure the effectiveness of its programs, particularly at schools most affected by poverty. Students in the District and Virginia use similar tests to measure student achievement.

Countywide, Montgomery's public school students scored in the 87th median national percentile in language mechanics, the 79th percentile in math and the 73rd percentile in reading -- all improvements over 2003 results. Students scored in the 83rd percentile in math computation, the same as last year after previous improvements, and the 68th percentile in language, the same as the past few years.

The 2004 CTBS percentile ranks for the county's black and Hispanic students were considerably improved from last year in reading, language and math. Hispanic children improved in math computation as well, while black students stayed the same. Both groups had no gain this year in language mechanics.

Except for Hispanics' reading scores, both groups scored above the national 50th percentile in all subjects. National percentile scores for whites and Asians remained the same as last year in most categories, improving only in math for white students and language mechanics and math for Asians.

Whites and Asians in Montgomery County scored above the 80th percentile in nearly every subject.

Second-graders learning English as a second language, receiving special education services or living in poverty improved in nearly all subjects since last year.

County Executive Douglas M. Duncan (D) said the test results will make it easier to get the political support needed to expand school improvement programs. "It's extraordinary news. It's exactly what we'd been hoping for," he said.

Although the county has been facing budgetary strains, Weast plans more initiatives. In the budget approved this month, Montgomery County opened 250 more preschool slots for needy children; Weast hopes an additional 750 will be added in following years.

At the Board of Education's request, and in compliance with an eventual state requirement, the budget includes funds to open all-day kindergarten at 17 more elementary schools, part of a plan to provide it throughout the county by 2007. Now, 56 schools have all-day kindergarten, in addition to smaller classes through second grade.

"I want the community to understand that this makes a statistical, measurable difference, and they should want it everywhere," Weast said.

Today, Weast will also announce an expansion of the Reading Together program that will provide one-on-one tutoring to 864 second-graders in the focus schools who can read but need help with comprehension.

And starting next year, teachers in some early grades will have frequent, short diagnostic assessments to give students and handheld wireless devices on which to record the results, school officials said.