When I double checked all our work so far it didn't work because I had neglected the worth.js line in my index.html.
So to help you, here's the latest index.html:

<html>
<head>
  <title>Yahtzee Solitaire</title>
  <link rel='stylesheet' href='styles.css'>
  <script src='one_row.js'></script>
  <script src='worth.js'></script>
  <script src='get_cns.js'></script>
  <script src='cell_clicked.js'></script>
</head>
<body>
  <div class='row'>
    <script>one_row();</script>
  </div>
</body>
</html>

And here's worth.js:

function worth(arr) {
  return 5;
}

So now it's time to create the worth function properly.