my @sum_values; my $x = 0; foreach my $key ( keys %ifSpeeds ) { if ($counter <= 8) { $sum_values[$x] += $ifSpeeds{ $key }; $counter++; } else { $x++; $sum_values[$x] = $ifSpeeds{ $key }; $counter = 1; } } for (my $x = 0; $x <= $#sum_values; $x++) { print "$x) $sum_values\n"; }