New report cards will allow elementary school students in Fairfax County to receive separate marks for effort and achievement beginning in September.

The new grading system, designed to reward students who try hard but still have trouble succeeding on tests, was approved unanimously by the county School Board last night and will replace a version in use since 1976.

The move makes Fairfax the first major Washington area school district to distinguish between effort and achievement in every subject.

The report cards now in use list effort as a single grade in a second section among other work and social skills such as courtesy and self-control.

On the new card, teachers will award the county's 60,000 first- through sixth-graders two grades in art, health, oral communication, reading, spelling, written communication, math, music, physical education, science and social studies.

The revised form, developed over four years and tested in 24 of the county's 129 elementary schools, is supported by administrators, teachers and parents.

In other action last night:

The board unanimously agreed to make a semester-long sex education class an elective for high school juniors and seniors instead of a graduation requirement.

Officials proposed the change to allow students flexibility in meeting academic diploma requirements. However, even as originally planned, the course allowed students to "opt out" with a parent's signature.

The board unanimously approved its annual update of the five-year capital improvement program, a planning document that outlines future building and renovation projects. The $695.5 million program includes few new items, but does restore plans for a new elementary school in the Kingstowne area that had been shelved because of the slumping economy.

On a 6 to 4 vote, the board rejected as premature a move by Springfield representative Anthony Cardinale to plan for a new high school in the Pohick area.

School officials presented their annual affirmative action report, which showed that the district met 12 of 15 hiring goals last year, including those for teachers and educational administrators. Nearly 12 percent of the system's teachers are minorities, the highest level in county history.

However, some consider the objectives outdated because they were set in 1984 and Fairfax classrooms have become far more diverse since then. Officials plan to revise the goals using this year's census data.