JSFiddle - React, Tailwind, and code Playground

HTML

From: 
<table><tbody>
    <tr><td>a</td><td>1</td></tr>
    <tr><td>b</td><td>2</td></tr>
    <tr><td>c</td><td>3</td></tr>
    <tr><td>d</td><td>4</td></tr>
    <tr><td>e</td><td>5</td></tr>
    <tr><td>f</td><td>6</td></tr>
    <tr><td>g</td><td>7</td></tr>
</tbody></table>
To:
<table><tbody>
    <tr><td>a</td><td>b</td><td>c</td><td>d</td>
        <td>e</td><td>f</td><td>g</td></tr>
    <tr><td>1</td><td>2</td><td>3</td><td>4</td>
        <td>5</td><td>6</td><td>7</td></tr>
</tbody></table>

JavaScript

$('table').each(function() {
    $(this).find('tr td:first-child'); // I'm lost here
    $(this).find('tr td:nth-child(2)'); // same here
});