JSFiddle - React, Tailwind, and code Playground

HTML

<table border="1">
<tr>
<th></th>
<th>col 1</th>
<th>col 2</th>
<th>col 3</th>
</tr>
<tr>
<th>row 1</th>
<td>3</td>
<td>4</td>
<td>5</td>
</tr>
<tr>
<th>row 2</th>
<td>13</td>
<td>14</td>
<td>15</td>
</tr>
</table>
<div class="tot">
</div>

CSS

.sel {
    background-color: red;
}
.tot {
    float: right;
    border: 2px solid green;
}

JavaScript

$('td').on('click', function(){
    $(this).toggleClass('sel');
    calcTot();
});
$('tr:first th').on('click', function(){
    $('tr:not(:first) td:nth-child('+($(this).index()+1)+')').toggleClass('sel');
    calcTot();
});
$('tr:not(:first) th').on('mousedown', function(){
    $(this).closest('tr').find('td').toggleClass('sel');
    calcTot();
});

function calcTot() {
    var tot = 0;
    $('td.sel').each(function(){
        tot += 1 * $(this).text();
    });
    $('div.tot').html(tot);
}