Stage two, devising a plan. Here the student makes use of his past experience to decide on the method of solution. At this stage he asks himself three questions,

A. Do I know a problem similar to this one? Do I know a problem similar to this one?

B. Can I restate the goal? Can I restate the goal in a different way that will make it easier for me to use my past experience? Polya calls restating the goal working backwards.

C. Can I restate what is given? Can I restate what is given in a way that relates to my past experience? Polya calls restating what is given as working forward.

The students stays at stage two until he has the flash of insight. If necessary. he can put the problem to one side for a while and then come back to it. Eventually, he will see how the problem can be done.

Stage Three. Carrying out the plan. The students carries out the plan of solution, check each step.

Stage Four, Looking back. The student checks his answer in some way, perhaps by using another method, or whatever. Having done that, he makes it part of his experience by asking himself, Can I use this result or method for other problems?

I will repeat again that not all problems are like the mathematics problems that Polya is thinking about. Not everyone problem is solvable, and some may even have no satisfactory solution.

Nevertheless, it is probably a good idea to do what Polya has done. That is, when you are successful in solving a problem, analyse how you have done it, and remember your method for the next time.