<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<form oninput="x.value=parseInt(a.value)+parseInt(b.value)">0
<input type="range" id="a" value="50">100 +
<input type="number" id="b" value="25"> =
<output name="x" for="a b"></output>
</form>
<p>Multiplication:</p>
<form oninput="d.value = e.valueAsNumber * f.valueAsNumber">
<input type="number" id="e"> *
<input type="number" id="f"> =
<output name="d" for="e f"> </output>
</form>
</body>
</html>