Require students to assess their mastery of the objective. At the close of the lesson, bring the attention of the class back to the objective and ask, rhetorically, for students to determine for themselves how well they mastered the concept. If the classroom rapport allows, ask students to apply the five-finger rule and show you the results of their self evaluation (five fingers indicate complete understanding; students holding up fewer than five fingers should be asking questions). If the class is more reserved, distribute index cards and ask students to write an answer to the objective. They should give the card to you as they leave. These exit passes will provide you with an immediate assessment of objective mastery as well as a great review at the opening of the next day's lesson.