You're asking the wrong question .... while knowing how to sort by numbers would be usefully, you will learn a lot more by going to Tutorials and reading the articles there. Hint: start with Welcome to the Monastery.

The answer you are looking for is available in: 2252.

Or, on your machine, try: perldoc -f sort, or see perlfunc:sort if perldoc doesn't work for you. Similarly, you can find the man pages and FAQs at http://www.perldoc.com/.