Two newbie questions

This should go as a helper instead. Helpers are methods (functions) accessible from your views (rhtml files).

In your Hello Helper file you would have:

def times_two(incoming_value)
incoming_value * 2

end

In your Hello Controller, your index method would simply be:

def index
end

Which calls your hello/index.rthml file, where you would have:

<%= times_two(5) %>

Which should display 10.