LinuxQuestions.org - [Perl] basic byte conversion script

I am very new to Perl and wrote this very simple to convert bytes to KB to MB to GB. So far it's working fine. But I tried to use "%g" in place of "%f" - which according to Learning Perl 4th ed. automatically
chooses float, integer etc. But it was not giving desired output. If anyone could tell me why I can't seem to use %g and also make some comments on the current code then that would be much appreciated.
Here's the code

Code:

#!/usr/bin/perl

use strict;

use warnings;

print "enter the value\n";

chomp (my $value=<STDIN>); 

my $kilo = $value/1024;

my $mega = $kilo/1024;

my $giga = $mega/1024;

print "the value is $value\n";

printf "%0.2f KB\n", $kilo;

printf "%0.2f MB\n", $mega;

printf "%0.2f GB\n", $giga;