A photo booth charges a $500 fee for two hours at a party, plus $50 per additional hour. Cindy doesn't want to spend more than $700 on the photo booth rental. What is the maximum number of additional hours (beyond the first two) that Cindy can rent the photo booth for her party?
The cost for the first two hours is $500.
Cindy wants to spend no more than $700, so she has $700 - $500 = $<<700-500=200>>200 left to spend on additional hours.
Cindy can therefore rent the photo booth for $200 / $50 = <<200/50=4>>4 additional hours. Answer: \boxed{4}.