index.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <link rel="stylesheet" href="stylesheet.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
  <script src="http://cdnjs.cloudflare.com/ajax/libs/mathjs/3.4.1/math.min.js"></script>
</head>
<body>
  <div class="equation">
    <div class="equationText"></div>
    <div class="sumInput">
      <input type="text" name="answer" class="answerText" maxlength="3"/>
    </div>
  </div>

  <div class="debug"></div>


  <script src="game3.js"></script>
</body>
</html>