The world of the written word is an obvious one. Billboards, road signs, digital media, newspapers, magazines, and books surround us. Mathematical messages are more subtle, although equally part of our everyday life. Looking out across a cityscape, we see buildings that could not have been constructed without extensive use of mathematical principles. In the grocery store we buy a vast variety of food, knowing that every item we pay for has been measured, weighed, or packed according to volume. To get to the store we climb into a car that has been built using mathematical calculations, fi ll it with carefully measured gasoline, and drive mathematically derived distances. Once our food is home, we can put it into a refrigerator cooled to a mathematically calculated temperature or into an oven heated with similar calculations. Even the simple act of making a bed is a mathematical one as we toss fresh (rectangular) sheets into the air, let them land in a symmetrical position, and, at least casually, calculate the measurements of bed and sheets to ensure a reasonably ordered fi nished product.