BOSTON (AP) -- Massachusetts fourth- and eighth-graders lead the country in reading and math scores, although grade four reading levels have slipped in the state and persistent achievement gaps remain.
Massachusetts ranked first in eighth-grade mathematics, and tied for first in fourth-grade reading, fourth-grade mathematics and eighth-grade reading, according to the 2013 National Assessment of Educational Progress exam.
On all four tests, Massachusetts students scored well above the national average.
But in grade four reading, the average score for Massachusetts students dropped by five points compared with 2011, the last time the test was given.
Massachusetts was one of only three states in the nation to see a statistically significant decline in grade four reading scores between 2011 and 2013.
The performance of Massachusetts students held steady on the three other NAEP tests -- reading at grade eight and mathematics at grades four and eight.
Education Commissioner Mitchell Chester called the dip in grade four reading scores a "cause for concern."
He said the state is addressing the problem by upgrading the curriculum, providing schools with more help in preparing students for college or careers and giving teachers more focused feedback to improve their performance.
He said new state standards also reinforce the importance of reading, writing, speaking, and listening across all subject areas.
The scores also reflected a stubborn gap in the test scores of white students compared to black and Hispanic students.
In all four tests, white students outscored black and Hispanic students while Asian students scored at or above the level of white students.
In eighth-grade mathematics, for instance, 63 percent of white students scored proficient or above compared with 28 percent of black students, 28 percent of Hispanic students and 78 percent of Asian/Pacific Islander students.
The tests also showed that girls outperformed boys on both reading tests, while boys and girls scored similarly on the two math tests.
State officials said the latest scores mark the fifth straight cycle -- 2005, 2007, 2009, 2011, and 2013 -- in which Massachusetts students have scored first or tied for first on all four tests.
"I couldn't be more proud of our students, teachers, and school administrators whose dedication and hard work made this remarkable achievement possible," Gov. Deval Patrick said in a statement.
Nationwide, just 42 percent of fourth-graders and 35 percent of eighth-graders scored at or above the proficient level in math. In reading, 35 percent of fourth-graders and 36 percent of eighth-graders hit that mark.
The tests assess representative samples of students in all 50 states.
In Massachusetts, 9,300 students were randomly selected at grade four to take the reading or mathematics test, and 8,500 students were randomly selected at grade eight to take a reading or mathematics test.
The scale for reading and mathematics ranges from 0 to 500.