Reading and math scores on Maryland’s standardized tests for elementary and middle school students dropped statewide in 2013, a decline educators blame on the transition to new national academic standards that they say do not align with the old exams.

A Washington Post analysis of test data that the state released Tuesday shows that almost every Maryland county saw test scores falter at the elementary and middle school levels.

Montgomery County saw some of the sharpest declines, including a 12 percent drop in the number of students who passed the state’s third-grade math exam. Montgomery’s overall passing rate for elementary math and reading fell nearly four percentage points overall — to 87 percent — the lowest rate the school system has seen in the past six years. Prince George’s County remained near the bottom of the state list, falling more than three percentage points at the elementary level and holding steady in middle school.

State and local school officials said they expected the scores to dip as they roll out classroom instruction that meets new national education standards — known as Common Core — yet continue to use a statewide test based on old academic guidelines.

With 45 states and the District adopting the new Common Core standards, which advocates say are more rigorous and provide the framework for more uniform K-12 education nationwide, other states probably will see similar test-performance declines until new Common Core tests are introduced in 2014. Virginia did not sign on to Common Core.

Who's learning more among Maryland students

Because of the difference between what was taught in the classroom and what appeared on the test in Maryland this year, some students answered test questions about material they were never taught, officials said. Or they spent less time learning certain concepts because the material is covered in greater depth in later grades under Common Core.

The Post’s analysis combined passing rates for reading and math. It found that the statewide average passing rate at the elementary level, which includes third-, fourth- and fifth-graders, was 85 percent, down from 88 percent last year. At the middle school level, which includes sixth-, seventh- and eighth-graders, Maryland students had an average passing rate of 78 percent, down from 79 percent.

Maryland officials cautioned that the overall decline in state test scores does not indicate that children are learning less.

“It means we are in transition,” State Superintendent of Schools Lillian M. Lowery said, adding that the state’s 24 school systems largely attributed the declines to the old test. “Nobody likes a drop, but we have to tell the story why.”

The Obama administration and the U.S. Education Department have endorsed the Common Core State Standards — guidelines written by governors and state education officials from both parties — awarding federal funding to states that adopt them. The rollout has drawn criticism, in part because some view it as federalizing education and in part because teachers and parents complain that schools were not adequately prepared to shift gears to the new standards.

“Maryland is doing what’s in the best interest of its students by raising standards and is being transparent about the challenge of aligning those new standards with current curricula,” said Daren Briscoe, a spokesman for Education Secretary Arne Duncan. “As we’ve seen in other states, a higher bar for all students and better measures of student learning are well worth a temporary drop in test scores during a transition to higher expectations.”

Montgomery School Superintendent Joshua P. Starr said county officials analyzed this year’s test data and determined that students scored higher on test questions that were similar to questions they might expect under Common Core.

Starr said the slide in scores highlights the “incredible misalignment” between a “lame-duck test” and Common Core.

The pronounced drop in third-grade math scores makes sense in Montgomery, Starr said, because those students have been learning under Common Core since kindergarten.

For example, Montgomery students used to learn statistics and probability in elementary school. But under Common Core, students are not scheduled to learn probability until middle school and do not start learning statistics until after the state’s current standardized test is administered. Montgomery also saw drops in third-grade math related to geometry and measuring, which used to be taught for four weeks in kindergarten through third grade and now are taught for a week, with deeper focus in later years.

“In some ways it’s good news,” said Starr, who has called for a moratorium on standardized testing until new assessments are available. “It means that our teachers and our staff and our leaders are doing exactly what we’ve been asking them to do. We’ve asked them to focus on Common Core.”

Montgomery parent Amanda Graver said the declining test scores aren’t a concern.

“I believe the Common Core curriculum is more rigorous and in-depth,” said Graver, recent co-chair of the curriculum committee for the Montgomery County Council of Parent-Teacher Associations. “Just because we have changed what we want [students] to learn, it doesn’t mean they’re learning less.”

InPrince George’s, where County Executive Rushern L. Baker III (D) has raised vocal concerns about the overall pace of academic achievement, elementary passing rates dropped to 77 percent, lower than all Maryland jurisdictions except the Eastern Shore’s Dorchester County (75 percent) and Baltimore City (70 percent).

A. Duane Arbogast, acting deputy superintendent for academics in Prince George’s, blamed the decline in part on the changes in testing for special education students. For the first time, special education students took the general assessments this year.

In some instances, the declines in Prince George’s were not as great as those seen statewide, or in some other districts.

Arbogast said Prince George’s made changes in learning standards in kindergarten through second grade this year and “took pains not to drop things that we knew would be tested items” in other grades.

Christian Rhodes, an education policy adviser for Baker, said the new test scores underscore the need to address county education, especially in its most challenging communities.

“These test scores do not change the course the county executive has for improving education across the county,” Rhodes said.

Education officials said Maryland’s standardized test scores probably will drop again next year, when some students continue to take the old exam while others pilot the Common Core-aligned tests that are set to debut in the 2014-15 school year.

“A drop in scores does not represent a drop in student achievement,” Maryland Gov. Martin O’Malley said. “We will continue to support our students and educators during the next few years as we make a transition that better prepares them to compete globally.”

Ted Mellnik and Lyndsey Layton contributed to this report.