D.C. test scores released Friday morning show a mostly flat trend line for achievement in the city’s school system compared to the year before.

Results from the 2011 D.C. Comprehensive Assessment System for the D.C. Public Schools show that pass rates for elementary reading were down 1.1 percentage points, to 43 percent, and for elementary math were down 0.8 points, to 42.3 percent.

In secondary grades, DCPS pass rate for reading rose 1 point, to 44.2 percent. For secondary math, it rose 2.7 points, the largest gain, to 46.4 percent.

City officials stressed the positive notes, framing the scores in relation to 2007, the year a major reform push began, rather than annual progress.

Secondary math scores have risen steadily since 2007, and every grade is performing at a higher level in math since 2007.

“ We have made important progress in all of our public schools since 2007 when we placed our schools under the authority of the mayor,” said Mayor Vincent C. Gray (D). “We have much to celebrate and even more work to do.”

Schools Chancellor Kaya Henderson noted gains by middle schoolers since 2007. Grades 7 and 8, she said, were top performers in math in 2011, with 49 percent of seventh-graders and 51 percent of eighth-graders scoring at or above the proficiency level, which is equivalent to passing.

“Today seventh- and eighth-graders have shown they can move us forward by making steady progress in reading and climbing to the top in math proficiency,” Henderson said.

Scores for charter schools were also to be released Friday.

Scores on the DC-CAS, given to all public and public charter school students in grades 3 through 8 and grade 10, trended upward for several years until 2010.

The 2011 scores were released as concern about cheating on the high-stakes tests continues to surface. A District official confirmed Thursday that the U.S. Department of Education has joined D.C.’s Inspector General’s office in an investigation of excessive answer sheet erasures at more than 100 schools that indicate possible cheating on the DC CAS in 2008 to 2010. The local probe was triggered by a March story in USA Today.

In Atlanta, 178 teachers and principals in 44 public schools cheated on the 2009 tests, according to a state investigation, either by lending improper help to students or altering answer sheets. Last month Maryland announced that widespread cheating on 2009 and 2010 state tests had been uncovered at two Baltimore elementary schools.

Some District parents and community leaders say the erasure issue is casting a shadow over the testing system. Data from 2009 and 2010 show that scores dropped at most schools the year after they were flagged for excessive erasures, raising questions about whether heightened security curbed abuses. School-by-school results for 2011 won’t be available until next month.

“If they do drop, that’s further evidence that there was extensive cheating,” said Mark Simon, a parent at School Without Walls and an education analyst at the Economic Policy Institute, a liberal think tank.

Asked if the widespread misconduct uncovered in Atlanta--where two former prosecutors and dozens of state agents were deployed to investigate--gave him any pause about test security issues in the District, Gray said that it did not.

“It does not to this point,” he said at his weekly press briefing Wednesday. “We’ll watch that carefully as you might imagine. We’ll ask the state superintendent to pay close attention to it as well.”