my %phrases = (
 "phrase 1" => {
   qty        => 1,
   qtySum     => 5,
   qtyCont    => 8,
 },
 "phrase 2" => {
   qty        =>10,
   qtyCont    =>34,
 },
 "phrase 3" => {
   qty        =>1,
 },
);

for my $k (keys %phrases) {
 # update
 # $phrases{$_}->{ qtyTotal} = sub { qtyTotal($_) }
 $phrases{$k}->{ qtyTotal} = sub { qtyTotal($k) }
}

sub qtyTotal{
 my $qty = 0;
 my $key = shift;
 my $phObj = $phrases{$key};
 foreach my $qType ('qty', 'qtySum', 'qtyCont'){
  $qty += $phObj->{$qType} if exists $phObj->{$qType};
 }
 return $qty;
}

##</code><code>##

for my $k (keys %phrases) {
 # update
 # my $ref = $phrases{$_};
 my $ref = $phrases{$k};
 $ref->{ qtyTotal} = sub { qtyTotal($ref) }
}

sub qtyTotal{
 my $qty = 0;
 my $phObj = shift;
 foreach my $qType ('qty', 'qtySum', 'qtyCont'){
  $qty += $phObj->{$qType} if exists $phObj->{$qType};
 }
 return $qty;
}

##</code><code>##

print "${ \$phrases{'phrase 2'}->{'qtyTotal'}->() }\n";

##</code><code>##

package Qty;
sub new {
    my $class = shift;
    bless { @_ }, $class;
}
sub qtyTotal {
    my $phObj = shift;
    foreach my $qType ('qty', 'qtySum', 'qtyCont'){
        $qty += $phObj->{$qType} if exists $phObj->{$qType};
    }
    return $qty;
}

package main;

my %phrases = (
 "phrase 1" => Qty->new(
   qty        => 1,
   qtySum     => 5,
   qtyCont    => 8,
 ),
 "phrase 2" => Qty->new(
   qty        =>10,
   qtyCont    =>34,
 ),
 "phrase 3" => Qty->new(
   qty        =>1,
 ),
);

print "${ \$phrases{'phrase 2'}->qtyTotal() }\n";