title: Summation of Equation Program
body: <p>So basically I'm trying to make a program that will do equation for every value of nStart to nEnd. This is my code so far</p>
  
  <pre><code>def summation(nStart , nEnd , eqn): 
      sum = 0
      while nStart - 1 != nEnd:
          sum = sum + eqn
          nStart += 1
      return sum
  
  print summation(1 , 5 ,  n + 1)
  </code></pre>
  
  <p>I get that n is not defined in the last line. I guess it's because I have n + 1 but how do I solve that? I tried making n = 0 but then that doesn't help because then eqn is just 1 and not an equation. </p>