    <!DOCTYPE html>
    <html>
    <head>
      <meta charset="UTF-8">
      <title>다중 반복문으로 구구단 출력하기</title>
      <link rel="stylesheet" href="style_js.css">
    <body>
      <script>
        let dan, num;
        for (dan = 2; dan < 10; dan++){
          document.write(dan + "단: ");
          for (num = 1; num < 10; num++){
            document.write(dan + "X" + num +  "=" + dan * num + " ");
          }
          document.write("<hr>");
        }
      </script>
    </body>
    </html>