Hundreds of teenagers grudgingly walked toward Lang Middle School on Tuesday. The kids had to return to the East Dallas campus during summer break to retake the state's math exam after "severe testing irregularities" were discovered.

"I don't know how I will do," Sharde Alexander, 14, said before entering the school. "I only missed four" on the previous test.

Lang's recent eighth-graders were given less than two weeks' notice that they would need to return to take the exam – or risk not being promoted to ninth grade.

The Texas Education Agency invalidated their exams earlier this month after Dallas ISD officials reported the irregularities, which district officials don't believe were caused by students. Of about 400 students affected, all but 78 showed up for the retest, DISD spokeswoman Sandra Guerrero said. TEA spokeswoman DeEtta Culbertson indicated that monitors for TEA said the testing went fine, other than a concern that seating charts were not provided for all classes.

DISD and TEA officials have not elaborated on the testing irregularities or confirmed whether cheating on the test occurred.

They say the investigation is ongoing. Dallas ISD officials have said previously that concerns were brought to state officials earlier in the year and at that time, it was decided that there was not yet enough evidence to require a retest.

Later, state officials said the unusual step should be taken.

Some students said they thought it was unfair they had to return during summer break to retake the exam. And those who achieved the "commended" level on the earlier test were especially worried about whether they could do it again.

Niger Khalid, 14, walked with Sharde to the campus Tuesday. Both students wondered what would happen if they just skipped the test, but decided to go ahead and take it.

"I'm mad," said Niger, who said she had received a commended on the exam. "How you going to think somebody cheated because some of us made good scores?"

Students who did not retake the exam will have to go before a grade placement committee to advance to ninth grade, according to TEA. Eighth-graders must pass the Texas Assessment of Knowledge and Skills exam in math and reading to be promoted.

Results of the retaken tests are expected to be available to parents by the third week in July.

Trustee Ron Price has said the district was tipped off to the irregularities by "a tremendous amount of kids who had the commended label" on the exam. Some parents said Tuesday that their children are being unfairly stereotyped and shouldn't be doubted for making good scores.

"I feel like it's unfair because society has it that children in our neighborhood can't pass the test," said Bernard Baylor, whose daughter had to retake the exam. "But I'm a Christian, and I believe these children will pass it."

Baylor said his daughter is disappointed she had to retake the exam, but she's confident she will pass again. "She's energized," he said.

Maria Rico said she's certain that her son will do well on the test again.

"He worked hard last year," she said. "He's not worried about it."