Groups write non-technical geometric descriptions of graphs and exchange them with other groups. Then students try to recreate graphs from the descriptions. The exercise is appropriate for pre-calculus or beginning calculus students. This is a cooperative learning exercise. Each student is given a function definition and asked to graph the function, and then to write a non-mathematical description of the appearance of the function.
Students form pairs, with each partner having the same function.
Pairs attempt to find the function that fits the description. This may be an iterative process. You've got it. That can't be the function because it doesn't satisfy a particular aspect of the description. Additional rounds give the students practice matching functions to descriptions.