Table Traversing with Jquery

I have a cart page where the quantity is not the correct quantity as the products are sold in bulk (1, 10, 100 items).

What I am trying to achieve is getting the number of items in the pack, multiply by the quantity and display the total number of items.

Here's a JSFiddle and the code:

jQuery(document).ready(function($){
$( ".variant_title" ).each(function() {
  var str = $(this).text();
  var qty = $(this).nextUntil('input[id^=updates_]').val();
  console.log(qty);
  if ( str.indexOf('jackets') > -1 ) {
      unities = str.slice(18,21);
      if (unities === '100' || unities === '10 ') {
        console.log(unities);
        totalUnities = unities * qty;
        console.log(totalUnities); 
        $(this).append('<br />' + totalUnities + ' Unities');
      }
  } else {
      unities = str.slice(18,19);
      if (unities === '1') {
        console.log(unities);
        totalUnities = unities * qty;
        $(this).append('<br />' + totalUnities + ' Unity');
      }
  }
});
});

Table example

My problem now is traversing the DOM and getting the value of the input field next to the description and multiplying.

Does anyone know where am I making a mistake here?

Thanks