JSFiddle - React, Tailwind, and code Playground

HTML

<table class="tbl">
    <tr>
        <td id="one">500</td>
        <td id="two"><input type="text" /></td>
        <td id="three"><input type="text" /></td>
        <td id="four"></td>
    </tr>
</table>

CSS

.tbl td {border: 1px solid black}

JavaScript

$('#two > input, #three > input').bind('keyup', function () {
    var oneVal = $('#one').text();
    var twoVal = $('#two > input').val();
    var threeVal = $('#three > input').val();
    var result = oneVal - twoVal - threeVal;
    $('#four').text(result);
});