This activity consists of 2 parts created by different entities. Winston-Salem/Forsyth County Schools created a superior worksheet that goes with the Glencoe Publisher online simulation: How can fossil and rock data determine when an organism lived? The simulation has instructions on the left side of the screen with a bar that can be scrolled forward as you proceed. The actual simulation looks like a scientist at work in the field at several “dig sites” 1-3. The icons are interactive at the bottom of the page: a nail with a tag and a magnifying glass, the computer, a chisel and a specimen collection box. The dig site number is displayed at the top so students can keep track of which site they are using. The worksheet provides the background, procedure and data tables from each dig site organized in a way that the data can be easily transferred and analyzed.