JSFiddle - React, Tailwind, and code Playground

HTML

<table id="sample" border="1">
<tr>
    <td>1</td>
    <td>2</td>
    <td>1</td>
    <td></td>
    <td>1</td>
    <td>3</td>
</tr>
<tr>
    <td></td>
</tr>
</table>

JavaScript

$(document).ready(function() {
    
    var colTotal=0;
 var col=$("#sample tr td");
	$(col).each(function()
		{
				colData=$(this).text();
            if($.isNumeric(colData)){
				colTotal+=parseInt(colData);
            }
		});
	$('#sample tr:last td').text(colTotal);
									
});