old_contents: def calculateTip(total, rate):
      return total * rate
  
  print "The tip is "
  print calculateTip(37.50, .15)
  
new_contents: 
  #takes in user input and prints out the tip for the total bsaed on the rate
  def calculateTip():
      total = float(input("Please enter the total amount as a float: "))
      rate  = float(input("Please enter the tax rate: "))
      tip = total * rate
      print "The tip is: ", tip 
      return tip
  
  calculateTip()
  
subject: update tip-calculator to take user input