Most new homeschool parents assume that checking for understanding means asking questions. Did you read the chapter? What happened in the story? Who was the main character? Why did the colonists revolt? What are the three parts of a cell? It feels responsible. It feels thorough. It feels like the kind of thing a real teacher would do. And it works — up to a point. But there is a simpler, older, and considerably more powerful approach that most homeschool parents either stumble onto by accident or discover years into their journey wishing they had found it sooner.