use strict;
use warnings;

my $w1 = 'name1';
my $w2 = 'name2';

my $hash = {
    'name1' => [
               'property1,8.8016',
               'property2,4.5016',
               'property3,4.0873',
               'property4,7.0726',
               'property5,9.5121'
               ],
    'name2' => [
               'property6,5.6217',
               'property2,4.7993',
               'property7,4.2885',
               'property3,11.1250'
               ],
    'name3' => [
               'property8,5.6217',
               'property2,4.7993',
               'property1,4.2885',
               'property9,11.1250'
               ]
           };

my %sums;

for (@{$hash->{$w2}}) {
    @_ = split /,/;
    $sums{$_[0]} = $_[1];
}
for (@{$hash->{$w1}}) {
    @_ = split /,/;
    print "$_[0] = $_[1] + $sums{$_[0]} = " . ($_[1] + $sums{$_[0]}) .
+ "\n"
        if $sums{$_[0]};
}
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