$(function() {
  $("[id*=txtRate]").val("0");
});
$("body").on("change", "[id*=txtRate]", function() {
  var rate = parseFloat($.trim($(this).val()));
  if (isNaN(rate)) {
    rate = 0;
  }
  //Update the Rate TextBox.
  $(this).val(rate);
  //Calculate and update Row Total.
  var row = $(this).closest("tr");
  $("[id*=lblTotal]", row).html(parseFloat($(".quantity", row).html()) * parseFloat($(this).val()));

  //Calculate and update Grand Total.
  var grandTotal = 0;
  $("[id*=lblTotal]").each(function() {
    grandTotal = grandTotal + parseFloat($(this).html());
  });
  $("[id*=lblGrandTotal]").html(grandTotal.toString());
});

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