<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the exponential notation of a specified number.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var num = 5.56789;
var n = num.toExponential();
document.getElementById("demo").innerHTML = n;
}
</script>
</body>
</html>