Washington ? New math scores show fourth-graders made no gains since 2007, the first time in two decades they have failed to improve. Eighth-graders advanced for yet another year.

Education officials called the results troubling, even though it is impossible to know from one test whether progress over the long term has stalled.

“We’re clearly not requiring enough of our math teachers,” said David Driscoll, chairman of the board that oversees the tests and a former education commissioner in Massachusetts.

Teachers lack training even in his state, which posted the highest scores in math. When Massachusetts beefed up the math portion of the elementary teacher test in 2007, 55 percent of teachers failed, he said.

And yet teachers are crucial to learning. Driscoll noted that eighth graders whose teachers majored in math scored 9 points higher than other kids on this year’s test.