project-2_calculator/index.html

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8" />
    <title>Calculator</title>
    <link rel="stylesheet" href="css/index.css" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  </head>
  <body>
    <div class="center">
      <form name="forms">
        <input type="text" id="display" name="display" disabled />
        <div class="buttons">
          <input type="button" id="btn" value="7" />
          <input type="button" id="btn" value="8" />
          <input type="button" id="btn" value="9" />
          <input type="button" id="btn" value="/" /><br />
          <input type="button" id="btn" value="4" />
          <input type="button" id="btn" value="5" />
          <input type="button" id="btn" value="6" />
          <input type="button" id="btn" value="*" /><br />
          <input type="button" id="btn" value="1" />
          <input type="button" id="btn" value="2" />
          <input type="button" id="btn" value="3" />
          <input type="button" id="btn" value="-" /><br />
          <input type="button" id="btn" value="." />
          <input type="button" id="btn" value="0" />
          <input type="button" id="btn" value="+" />
          <input
            type="button"
            id="clear"
            value="C"
            onclick="document.forms.display.value=''"
          /><br />
          <input
            type="button"
            id="equal"
            value="="
            onclick="document.forms.display.value=eval(document.forms.display.value)"
          />
        </div>
      </form>
    </div>
    <script type="text/javascript" charset="utf-8" src="js/index.js"></script>
  </body>
</html>