JSFiddle - React, Tailwind, and code Playground
by MrTest
HTML
<table>
<tr>
<td> + </td>
<td> 1 </td>
<td> 3 </td>
<td> 6 </td>
<td> 7 </td>
</tr>
</table>
CSS
.url { background-color: #ccc;}
table { width: 80%; margin: 10px auto;}
table td {border: 1px solid #ccc; text-align: center;}
JavaScript
$('table tr td:contains(" + ")').each( function(){
$(this).addClass('url');
});