Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <div class="box">
        <input id="input" value="0" />
        <button id="up" onclick="counter(3)">*3</button>
        <p>Value <span id="output"></span></p>
    </div>
    <script type="text/javascript">
        function counter(val) {
            var value = document.getElementById('input').value;
            var newValue = parseInt(value, 10) * val;
            document.getElementById('output').innerHTML = newValue;
            return newValue;
        }
    </script>
</body>
</html>