calculator/index.html

<!DOCTYPE html>
<html lang="en" dir="ltr">

<head>
  <meta charset="utf-8">
  <link rel="stylesheet" href="style.css">
  <title>Calculator</title>
  <script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
  <script src="app.js" charset="utf-8"></script>
</head>

<body>
  <div class="container">
    <div class="output">
      <p>0</p>
    </div>
    <div class="row">
      <div class="column-1">
        <button class="number">1</button>
        <button class="number">2</button>
        <button class="number">3</button>
        <button class="number">4</button>
        <button class="number">5</button>
        <button class="number">6</button>
        <button class="number">7</button>
        <button class="number">8</button>
        <button class="number">9</button>
        <button class="number">0</button>
      </div>
      <div class="column-2">
        <button class="reset">CE</button>
        <button class="operator">+</button>
        <button class="operator">-</button>
        <button class="operator">*</button>
        <button class="operator">/</button>
        <button class="equals">=</button>
      </div>
    </div>
  </div>
</body>

</html>