This activity allows students to gain a visual perspective of important events from the geologic time scale and comprehend the history of the earth. The double-sided sheet provides three charts containing important events, their occurrence and the scale in centimeters. There are analysis questions provided for students to analyze their scales once completed or they could be used for a class discussion. Register tape is needed so that each group of students has a meter long piece of the tape. I usually made a 2 meter long teacher version going back to the formation of the planet so that the students could compare. The word document can easily be edited to personalize the activity according to your needs, especially since you may not choose to create your own scale for comparison.