I think the problem with a question like "How many gas stations do you think are in this town" is it is too simple to reach the answer, and the approximations a

I think the problem with a question like "How many gas stations do you think are in this town" is it is too simple to reach the answer, and the approximations are too vague. The solution for everyone is to google it. The approximation method requires some big assumptions about how many gas stations there are per-capita, or per-car, or per-area. I don't think anyone would be able to easily approach that off the top of their head and expect to get a reasonable answer. Just as approximation is a useful tool, knowing when it doesn't work is also useful. What would your approach be to work out how many gas stations are in your town? Have you done that calculation, and come out with a reasonable answer? What assumptions did you have to make?