“How to Solve It” (first published in 1945) is a small volume by mathematician George Pólya describing methods of problem solving. The book suggests the following steps when solving a mathematical problem:
1. Understand the problem.
2. Devise a plan to solve it.
3. Carry out the plan.
4. Revise and extend: look back on your work.
Further Reading:
https://en.wikipedia.org/wiki/How_to_Solve_It
https://en.wikipedia.org/wiki/Heuristic
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