Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<body>

<input type="number" id="myNumber" value="2"><br><br>

<button onclick="disableBtn()">Disable Number Field</button>
<button onclick="undisableBtn()">Undisable Number Field</button>

<p><strong>Note:</strong> input elements with type="number" are not supported in IE 9 and earlier versions.</p>

<script>
function disableBtn() {
    document.getElementById("myNumber").disabled = true;
}
function undisableBtn() {
    document.getElementById("myNumber").disabled = false;
}
</script>

</body>
</html>