The Washington Post reports that soon after Arne Duncan left his job as schools chief in Chicago to become one of the most powerful U.S. education secretaries ever, his former students sat for federal achievement tests. This month, the mathematics report card was delivered: Chicago trailed several cities in performance and progress made over six years. Miami, Houston and New York had higher scores than Chicago on the National Assessment of Educational Progress. Boston, San Diego and Atlanta had bigger gains. Even fourth-graders in the much-maligned D.C. schools improved nearly twice as much since 2003. The federal readout is just one measure of Duncan’s record as chief executive of the nation’s third-largest system. Others show advances on various fronts. But the new math scores signal that Chicago is nowhere near the head of the pack in urban school improvement, even though Duncan often cites the successes of his tenure as he crusades to fix public education.