This is a discovery activity to introduce the definition of a function through a vending machine. As a class or in small groups, students will add snacks into a vending machine. They will discuss the idea of the possibility of each input having one output; each input having more than out output; multiple inputs to have the same output, etc. I continue to refer back to the vending machine as we talk about the idea in terms of math in the notes.Please feel free to contact me if you would like an e