Why does my if statement get stuck on the first value?

I wanted to set a $levelNumber based on the number of Lessons. So I did the following:

  <?php
    $s = "Lesson 001: Vocabulary";
    preg_match("/([0-9]+)/", $s, $matches);
    echo $matches[1]; // => 001

    if ($matches[1] >= 060) {
      $levelNumber = "2"; 
    } elseif ($matches[1] >= 120) {
      $levelNumber = "3";
    } elseif ($matches[1] >= 180) {
      $levelNumber = "4";
    } elseif ($matches[1] >= 240) {
      $levelNumber = "5";
    } elseif ($matches[1] >= 300) {
      $levelNumber = "6";
    } elseif ($matches[1] >= 360) {
      $levelNumber = "7";
    } else {
      $levelNumber = "1";
    }
  ?>

But right now no matter how big the lesson is (e.g. 180) $levelNumber always outputs 2. And it outputs 1 when the lesson is under 048. I'm really confused.

This is the correct level with lesson:

Level 1: Lessons 1 to 60

Level 2: Lessons 61 to 120

Level 3: Lessons 121 to 180

Level 4: Lessons 181 to 240

Level 5: Lessons 241 to 300

Level 6: Lessons 301 to 360

Level 7: Lessons 361 to 420