Oakdale Elementary students returned to in-person classes for the second time in mid-February. In the first semester of last school year, 3% of Oakdale Elementary School’s third-graders got a D or F in reading. That was before the pandemic. This year, with a fluctuating mix of remote and in-person classes, 69% of Oakdale’s third-graders fell below a C. That’s one of the more extreme swings, but data on classroom grades provided by Charlotte-Mecklenburg Schools shows many schools have taken dramatic hits on measures of academic performance during the pandemic. Almost always, they’re schools like Oakdale in north Charlotte, a high-poverty neighborhood school where more than 80% of students are Black or Hispanic.