#!perl 

use warnings;
use strict;

my %arith;
$arith{"+"} = sub { $_[0] + $_[1] };
$arith{"-"} = sub { $_[0] - $_[1] };
$arith{"*"} = sub { $_[0] * $_[1] };
$arith{"/"} = sub { $_[0] / $_[1] }; 

my $Problem = "6 * 8";
$Problem =~ /^(\d*)\s(.)\s(\d*)$/;
my $Number1    = $1;
my $Number2    = $3;
my $Operator   = $2;
my $Op = $arith{$2} or die qq[wrong operator: "$Operator"];

my $Answer;

$Answer = &$Op($Number1, $Number2);

print $Answer, "\n";

__END__