No one should be allowed to make a remark about an answer unless they have a better one. Student will occasionally argue that they can learn by listening, and that they do not have to participate directly in the process or discussions in order to learn the methods. They are wrong. This puts the student right back in the memorization method. One must participate directly in order to learn how to solve problems.
Estimation is good, and often necessary, but problems have specific answers.
Guessing at answers without actually solving the problems will stop others from trying. Answers to simpler problems may be intuitive to some students, but, when required to actually work through the problems, students will often find out that the basis for even intuitive answers can often be abstract and challenging. Students should understand that in a problem solving class, getting the answer to a single problem is not as important as learning the problem solving process. If you find links that are either unsuitable or no longer current, please contact the TLC .