DALLAS — When Tha Cung looked over his sixth-grade class schedule, he took notice of the math block. He had been placed in an advanced class. “I didn’t know ‘honors’ even existed,” he said. Tha was ...

DALLAS — When Tha Cung looked over his sixth-grade class schedule, he took notice of the math block. He had been placed in an advanced class. “I didn’t know ‘honors’ even existed,” he said. Tha was ...