title: How to count number of digits?
body: <blockquote>
    <ol>
    <li><p><code>(CountDigits n)</code> takes a positive integer <code>n</code>, and returns the number of digits it contains. e.g.,</p>
  
  <pre><code>(CountDigits 1) → 1
  (CountDigits 10) → 2
  (CountDigits 100) → 3
  (CountDigits 1000) → 4
  (CountDigits 65536) → 5
  </code></pre></li>
    </ol>
  </blockquote>
  
  <p>I think I'm supposed to use the remainder of the number and something else but other then that im really lost. what i tried first was dividing the number by 10 then seeing if the number was less then 1. if it was then it has 1 digit. if it doesnt then divide by 100 and so on and so forth. but im not really sure how to extend that to any number so i scrapped that idea</p>
  
  <p>(define (num-digits number digit)
    (if (= number digit 0)
        1</p>