1. Understanding the problem

• What is the unknown?
• What are the data?
• What is the condition?

2. Devising a plan

• Do you know a related problem?
• Have you seen the problem before?
• Could you restate the problem?

3. Carry out the plan

• Check each step

4. Looking back

• Can you check the result?
• Can you derive the answer differently?
• Can you use the result, or the method, for some other problem?

(Polya, 1985)