<?php
$post_id = get_the_ID();
$viewed_values = get_post_meta($post_id, 'my_post_viewed');
$total_views = 0;
foreach ($viewed_values as $viewed_value) {
    $total_views += intval($viewed_value);
}
echo 'Toplam Görüntülenme Sayısı: ' . $total_views;
?>