DETROIT -- Results released Tuesday from a national achievement test show Detroit Public School scores were the lowest ever in the math category.

The National Assessment of Education Progress (NAEP) exam was taken by about 1,900 fourth- and eighth-graders.

The scores were based on a scale of 500. The national average was 239. The fourth-graders from Detroit scored 200.

Among eighth-graders, Detroit students scored 238, compared to the national average of 282.

According to the test results, 69 percent of fourth-graders and 77 percent of eighth-graders in Detroit scored below the basic math level.

"These numbers are only slightly better than what one would expect by chance as if the kids had never gone to school and simply guessed at the answers," said Michael Casserly, executive director of the Washington-based Council of the Great City Schools, which represents large urban school districts.

Test organizers said 18 urban districts took part in the NEAP. "The numbers are shocking and appalling and should not be allowed to stand," Casserly said.

The NAEP is an hour-long exam. It is scored in two ways: Average results are scored on a scale of 1 to 500 and in the second criteria, students are ranked from "below basic" to "advanced."

Detroit Public Schools Emergency Financial Manager Robert Bobb said it was not the fault of the students.

"It is directly the result of the failure to lead. It is a result of the failure to manage," said Bobb. "It is the result of the failure to establish rigorous academic, and strong academic standards. The results are the failure of the (school) system's leadership."

Reading and science results are scheduled to be released in the spring.