title: Error Message: TypeError: unsupported operand type(s) for -: 'str' and 'float'
body: <p>I'm writing a program for my GCSE coursework that works like a vending machine. I'm trying to minus a variable off of a re-written variable and for some reason it is just not working. Help?</p>
  
  <pre><code>This is my code:
  credit=raw_input("Please input your change, CAREFUL! This Machine only accepts 10p,20p,50p and £1: ")
  list1= ["1", "2", "3", "4", "5"]
  price1=0.65
  price2=0.70
  price3=0.50
  price4=0.70
  price5=0.80
  while (credit) == 0:
     (credit)=raw_input("Please input your change: ")
  products = (" 1) Kinder Bueno\n 2) Doritos Chilli Heatwave\n 3) Nestle Yorkie Bar\n 4) Coca Cola(Can)\n 5) Volvic Stawberry Water")
  print (credit)
  print ("The product selection is the following")
  print (products)
  (selection)=raw_input("Please select a product: ")
  if (selection) == (list1[0]):
     (new_credit)=int(credit-price1)
     print (new_credit)
  </code></pre>