* buy 2 get one free
* 3 for a dollar
* total bill generation
* Iterative
* Recursive with start & ending passed in each call
* Above Recursive method patched on to a Ruby Array
* Recursive method with a 'counter' passed along with every call
* Smallest temperature spread caclulator
* Smallest difference between goals scored "for" and "against"
* Strategy based workflow function
* Document the "find the smallest differential" algo in one place