A laboratory exercise that is commonly done in introductory chemistry is to measure the thickness of aluminum foil. Students, usually working in teams, are furnished with scales, beakers, rulers, etc. along with aluminum foil and asked to come up with a method for measuring this thickness. The most common group solution involves folding the foil multiple times in hopes of getting something reasonably thick to measure, and then taking the number of folds into account. A couple of years ago I had a student who had moved on from my biology class to a chemistry course ask if he could use the SEM to find the thickness. The final image -- shown with magnification and micron bar -- can be brought up under NIH Image on the computer and the thickness measure. The above images represent what became the class standard that year.