Boiling temperature is 212^{o} Fahrenheit;
100^{o} in Celsius.

Let's design and implement a GUI application that converts a temperature expressed in Fahrenheit into Celsius. As usual, there are three parts to the design:

- The Graphical User Interface.
- Listener methods.
**Application methods**.

Let us first look at the application methods. The formula for converting fahrenheit into Celsius is this:

celsius = (fahrenheit - 32) * 5/9

This is *algebra*, not Java.
Although the algebra looks much like Java,
some design decisions are needed.

Should you use integer variables or floating point variables to implement the formula?