Show on a scale
In the teacher’s tool kit one of the most useful resources is the trustworthy post-it notes. They can be used for almost every part of the lesson, but they come into their own when being used for assessment for learning.
Confidence scales are an amazing way of not only showing progression in a lesson but also the progress of the individual students within the lesson.
All you need to do is ask the students to write their name on a post-it and use the whiteboard to draw a scale of understanding, the students then add their name where they believe they currently are.
This is not a one-time thing, ensure the students understand that during the lesson you will be asking them to come and move the post-it note to see if their understanding has changed. You can make this a fixed point in the lesson or you can allow the students to move the post-it note when they feel they have grown in understanding; you tailor it to your classes.
This allows you to see groups of students are require more help. The students have been saying they know how to do it all, well, for the time being, they can help the middle students while you focus your efforts on the students that have no understanding.