Concrete is made from sand, gravel, and cement (which is made from shale, limestone, and the minerals quartz, gypsum, iron, alumina, manganese, and clay). Every year, 4700 lb of concrete is produced...

Concrete is made from sand, gravel, and cement (which is made from shale, limestone, and the minerals quartz, gypsum, iron, alumina, manganese, and clay). Every year, 4700 lb of concrete is produced for every person in the United States, so that our roads, homes, schools, businesses, factories, and so on can be built or maintained. Calculate how much concrete is produced for your entire class in one calendar year. (Source: Mineral Information Institute, www.mii.org.)