title: Error: (/) bad argument type: #<unspecified> Chicken Scheme Square root approximation
body: <p>I am following the SICP lectures from MIT, and this is what I tried to find the square root approximation of a number by Heron of Alexandria's method. This is my first time trying out lisp, sorry for making noobie mistakes.</p>
  
  <pre><code>(define guess 1)
  
  (define (avg a b)
    (/ (+ a b) 2))
  
  (define (try guess x)
    (if (goodEnough guess x)
        guess
        (improve guess x)))
  
  (define (improve guess x)
    (define guess (avg guess (/ x guess)))
    (try guess x)
    )
  
  (define (goodEnough guess x)
    (= guess (avg guess (/ x guess))))
  
  (print (try 1 25))
  </code></pre>
  
  <p>I am using Chicken scheme compiler to print this. This is the output:</p>
  
  <pre><code>Error: (/) bad argument type: #&lt;unspecified&gt;
  
      Call history:
  
      1.a.SquareRootApproximation.scm:29: try   
      1.a.SquareRootApproximation.scm:17: goodEnough    
      1.a.SquareRootApproximation.scm:27: avg   
      1.a.SquareRootApproximation.scm:19: improve     &lt;--
  </code></pre>
  
  <p><strong>Updated:</strong> I have changed my approach towards this problem using lisp with more abstraction, yet I can't figure out what this new error wants to imply. Any fixes? Thanks!</p>