When students finish an activity, often we ask them in a variety of ways to show how many answers they got right. The problem is then filling in the gaps in the student’s knowledge. In Carl Hendrick’s brilliant book “What does this look like in the classroom”, Dylan Wiliam says (and I’m paraphrasing) that essential if he were to rename what has now come to be know as AfL, he would call it ‘response teaching’. Thus, my response to the above issue is this.
When you are going through some work with students and have marked it, ask students to raise their hand if they got a question/problem/equation wrong. You can then take a tally and go through further examples of the question/problem etc which had the most incorrect answers. This instantly fills in the gap in their knowledge. I have used mini whiteboards for this as it suits the ‘ad hoc’ scenario of which I am describing but I am sure there are a number of other mediums through which to provide said feedback. If some students had the correct answer, why not get them to take the lead on creating and marking the new example?