Hinge questions act like a check point in your lesson. If students them get correct, they move on to the next activity. However, if students get the hinge question wrong, the teacher does a quick reteach, or pulls a small group, before moving on. The "hinge" means student progress can go in either direction. Either they move on because they have demonstrated mastery of a concept or skill, or they're redirected back for additional learning before attempting again.