After four folds, the napkin is about 0.4 inches thick. Doubling it 29 more times would produce a thickness of 216 million inches. A mile is about 63,400 inches, so the folded napkin would be a little over 3,400 miles thick. At this point it is useful to ask people to draw the behavior over time graph for the thickness of the napkin, assuming that they could accomplish one fold every second for 33 seconds. Depending on the time available, you may want to prepare other examples to further explore this dynamic.
Population growth is a dramatic illustration that piques people s interest.
You can say, We chose to illustrate 33 doublings in this activity for a reason. Today s global population is almost 33 doublings from the first person on Earth. More than 6 billion people currently live on the planet. In other words, an individual relates to the planet s population as the thickness of a single sheet of paper relates to the distance from Boston to Frankfurt. Suppose a water lily is growing on a pond in your backyard.