Exponential graphs are constant to the power of variable. A simple model of this would be the classic lily pad covering the pond question. Assuming if the lily pad double its population every day and the students want to clean the lily pad out of the pond the day before the entire pond is covered with lily pads. In the end, the students have to clean the pond up the day half of the pond is covered. This growth of the lily pad, when plotting, forms an exponential graph.