In Las Vegas, some teachers and students say the changes have led to gaming the system and a lack of accountability.

“If you go to a job in real life, you can’t pick and choose what tasks you want to do and only do the quote big ones,” said Alyson Henderson, a high-school English teacher there. Lessons drag on now, she said, because students can turn in work until right before grades are due.

“We’re really setting students up for a false sense of reality,” Ms. Henderson said.

“There’s an apathy that pervades the entire classroom,”