Control of the answer (verify). Based on their answers, students are encouraged
discuss their solutions. When they have got the same answers, they are asked to
retell their solving process and check whether they have really arrived at the right
solution. If their answers are different, they should determine whose is correct or
complete. They are also asked to reflect on what they had learnt for future
problems and tasks, and what kind of strategies are more efficient and can be
adopted later on.