**Re-usable code**

One
of the reasons for breaking code up into modules, *(such as Alice primitive methods
and functions)*, is to make them easily re-usable.

For example, the **world**
object has a function named **Math.sqrt**.

That function can be called to compute and return the square root of a number.

The Alice development team were good enough to write that code for us and to provide it in the form of a standard Alice function.

As a result, whenever we need to compute the square root of a number, we don't need to "reinvent the wheel."