JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>valor 1</td>
        <td>valor 2</td>
        <td>total</td>
    </tr>
    <tr>
        <td>
            <input type="number" min="0" onchange="calcula()">
        </td>
        <td>
            <input type="number" min="0" onchange="calcula()">
        </td>
        <td>
            <input type="text" readonly value="0" id="teste">
        </td>
    </tr>
</table>

JavaScript

function calcula() {
    var inputs = document.querySelectorAll('input[type="number"]');
    var soma = 0;
    for (var i = 0; i < inputs.length; i++) {
        soma += parseInt(inputs[i].value) || 0;
        document.getElementById("teste").value = soma;
    }
}