How to collect a user's inputted integers into an array (sort it) and outlut minimum value to web page

I am beginner and wanna to ask u guys! I have a code but it doesn work. I want to collect all data in array after that this array will be sorted by the value and output the minimum value on the web page. I create a code to collect input values from user but dont know what to do next. Could u help me? (the output should look like this: your math score is low (3) u should improve this section) Please guys!

<script>
 var myItems = []

function add(e) {
  var obj = {};

  $('#addItem input[type="text"]')
    .each(function() {
      obj[this.name] = this.value;
    });
  myItems.push(obj);
}

function test(e) {
  alert(JSON.stringify(myItems));
}
$(document).ready(function() {
  $('#add').click(add);
  $('#test').click(test);
});

</script>

<form id="addItem">
    <table id="tblSearchTally">
        <tr>
            <td>Biology:<input type= "text" value ="1" name="plank" id="plank"></td>     
        </tr>
        <tr>
            <td>Chemistry:<input type= "text" value ="4" name="width" id="width"></td>      </tr>
        <tr>
            <td>Physics:<input type= "text" value ="6" name="length" id="length"></td>      </tr>
        <tr>
            <td>Math:<input type= "text" value ="4" name="thickness" id="thickness"></td>     
        </tr>
  
    </table>
    <p><in