The Problem

We need to convert a temperature measured on the Fahrenheit scale to its equivalent on the Celsius scale.

An aside: This is not a realistic programming problem. It would be faster to use a hand held calculator to do this than to write a computer program to do it. But, it would not be practical to use a hand held calculator to convert 20 years worth of daily temperatures stored in a file from Fahrenheit to Celsius, and before we can change a file full of temperatures we need to figure out how to change just one of them.

Now we will work through the solution of this problem as follows:

1. Solving the problem by hand to make sure we know how to do it.

2. Consciously identifying our solution method, i.e. the solution algorithm.

3. Translating that algorithm into Python.

4. Entering and running the resulting program and verifying that it works.