somar-coluna-tabela

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<table id="products-table">
    <tbody>
        <tr>
            <td>10</td>
            <td>produto1</td>
            <td>1</td>
            <td>3</td>
        </tr>
        <tr>
            <td>20</td>
            <td>prodto2</td>
            <td>2</td>
            <td>4</td>

        </tr>
    </tbody>
    <tfoot>

    </tfoot>
</table>
<script>


    function getTotal(column = 1) {
        let result = 0;
        let columns = $("#products-table tr td:nth-child(" + column + ")");

        columns.each(i => {
            result += parseInt($(columns[i]).html());
        });

        return result;
    }

    console.log("Soma da primeira coluna: " + getTotal(1));
    console.log("Soma da terceira coluna: " + getTotal(3));
    console.log("Soma da quarta coluna: " + getTotal(4));
</script>