Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
<label>First number:&nbsp;</label><span id="firstNumber">0</span>
<label>Second number:&nbsp;</label><span id="secondNumber">0</span>
	<div> <input type="button" id="firstNumberButton" value="this adds +1 to first number"> </div>
	<div> <input type="button" id="secondNumberButton" value="this adsd +1 to second number"></div>
	<br /><br />

	<input type="button" value="Click me to get result!" id="divider"/>	<br/>
	<label>result:&nbsp;</label><span id='result'></span><br />

<script>
			document.addEventListener("DOMContentLoaded", function() {
			document.getElementById('firstNumberButton').addEventListener('click', function() {
			document.getElementById('firstNumber').innerHTML++;
				});
			});
			document.addEventListener("DOMContentLoaded", function() {
			document.getElementById('secondNumberButton').addEventListener('click', function() {
			document.getElementById('secondNumber').innerHTML++;
				});
			});

</script>

<script>
        document.getElementById('divider').addEventListener('click', function() {
            let firstNumber = document.getElementById('firstNumber').value; //stores whatever is in the 'first-num' textbox into the variable firstNumber
            let secondNumber = document.getElementById('secondNumber').value; //stores whatever is in the 'second-num' textbox into the variables firstNumber
            let result = firstNumber / secondNumber; //stores whatever the value of the first number divided by the second number into the variable result
            //sets the innerHtml property of the span with id of 'result' to the value of the variable result.
            //a visual explanation of what the innerHtml property of a HTML element: <span>(Whatever the value is of the innerHtml property goes between the two span tags)</span>
            document.getElementById('result').innerHTML = result;
        })
    </script>