After going through the two main solution methods for the photo enlargement problem, the teacher asks the students how they can generalize.
Definition of Proportionality, Photo Enlargement Problem, Clip 3, 3:41
This video is an example of teacher questioning. Good questioning strategies are very useful when the students are working together in groups. It is important to help guide them without giving away the answers.
The students are able to solve the problem, but notice how teacher encourages them to explain their solutions, his questioning is very good.