One of the calculations that students learn in chemistry is percent composition. A fun way to approach this calculation is to have students use an inexpensive sugary gum that loses its flavor fairly quickly. (A restaurant I frequent gives out this gum with the check so I save it during the year for this activity.) Students open the packaging and use the packaging as a weighing dish for the gum. Then they chew until the sweet flavor is gone, and re-mass the gum. The difference is the mass of the sugar. Students can discuss sources of error such as the added mass of saliva on the gum after chewing.
I like to do a three way comparison with this activity. Some groups chew the sugared gum, some sugar free gum, and a third group chews a gum advertised as long lasting. The results between the three groups are very interesting.
While chewing, I ask students to read about what makes long lasting chewing gum last such a long time in this short magazine style reading about the use of nanoparticles to deliver flavor over time. The magazine is called "Nanooze," the gum article is in the food issue in 2009. The magazines are available as free class sets to teachers through the website: