use warnings;
use strict;
use Tk;
use Devel::Peek;

my $scale = '22.5 '; # note the space in the output as well
my $foo = 0 + $scale; # use in numeric context (set NV and IV)
Dump($scale);

my $mw = MainWindow->new;
$mw->Entry(-textvariable=>\$scale)->pack;
$mw->bind("<Key-Return>",\&calc);
calc();
MainLoop;

sub calc {
	print "str: <$scale> / num: <".(0+$scale)."> \n";
}

##</code><code>##

SV = PVNV(0x1e3f350) at 0x1e59a40
  REFCNT = 2
  FLAGS = (NOK,POK,IsCOW,pIOK,pNOK,pPOK)
  IV = 22
  NV = 22.5
  PV = 0x1e6f870 "22.5 "\0
  CUR = 5
  LEN = 10
  COW_REFCNT = 1
str: <22.5 > / num: <22>