The first this you want to do is use CGI;. The CGI.pm is the standard/recommended/highly praised way of access the arguments you seek.
Once you have 'use CGI;' at the top of your script then it is very simple

#!/usr/bin/perl -Tw
use strict;
use CGI;

my q$ = new CGI;

my $number = $q->param('number');
[download]

Make sure you perldoc CGI to read the docs for CGI.pl

grep

grep> cd pub grep> more beer [download]