title: summing a series of numbers entered by the user
body: <p>I'm learning from a book and here is my task:</p>
  
  <blockquote>
    <p>Write a program to sum a series of numbers entered by the user. The
    program should first prompt the user for how many numbers are to be
    summed. It should then input each of the numbers and print a total
    sum.</p>
  </blockquote>
  
  <p>I have pretty much no idea how to start on this. My first problem is just after the user definies how many numbers are to be summed, I don't know how to make use of the information to build the next input expression for exact numbers. </p>
  
  <p>If we knew before how many numbers the user will enter this would be no brainer but...</p>