Thinking method · Pólya, How to Solve It

The four steps

A general procedure for any problem you do not immediately know how to solve. Any problem where your first move would otherwise be to start doing something.

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A general procedure for any problem you do not immediately know how to solve.

The steps

1. Understand it. State what is unknown, what you are given, and what the condition connecting them is. Draw it if you can. Say it back in your own words.
2. Make a plan. Have you seen a problem with the same unknown? Can you solve a part of it? Can you solve an easier version and work up? Can you work backwards from the answer you want?
3. Carry out the plan. Check each step as you take it, rather than at the end.
4. Look back. Can you check the result a different way? Can you see it at a glance now? Can you use the method on something else?

When to use it

Any problem where your first move would otherwise be to start doing something.

What it will not do

It will not tell you which plan is right. It makes sure you have one, and that you understood the problem before making it.

Where it comes from: Pólya, How to Solve It. Described in our own words.