Geologic Time: on Adding Machine Tape

Time on Earth is LONG.
Time that Life has been on Earth is SHORT.
Time that People have been on Earth is VERY SHORT!

This project is a great way to show students tangibly how long Earth's timeline is. The scale for the measurements on the adding machine tape is  1 cm = 10 million years ( 1 mm = 1 million years). 
[We only labeled up the the Pre-Cambrian period]