Instead of letting the eternal, "I'm new here", teenager take your order ...
All that is needed is to put rows of dumb terminals (designed specifically for the fast food business at hand) where customers can muse out their own orders.
Order #18694All consecutive every day. If you don't use your order ... just walk out the door ... computer saves everything for posterity. Such information (about what you didn't buy) may also be useful to the company.
Those orders paid for go up on the TV screen and kids in the back make the order ... bring it to front ... you pick it up at "the next window".
So, employeewise, there is 1 money-taker, 1 order-giver-outer (if business is heavy), and whatever kids necessary to make burgers in the back (157 ? ... w/2 actually working?).
And lastly, (Glory, Glory, Hallelujah) 1 more kid to empty the trash cans, wipe & bus the tables, and clean the restrooms.