A toy manufacturing uses $40,000$ rubber wheels per year for its popular dump truck series. The firm makes its own wheels, which it can produce at a rate of $600$ per day. The toy trucks are assembled uniformly over the entire year. Carrying cost is $$1$ per wheel a year. Setup cost for a production run of wheels is $$40.$ The firm operates $240$ days per year. What is the approximate optimal run size $($Round up the number$)?$