What are some events that all of us have had in our lives? Ask the class "What are some events that all of us have had in our lives?" Make a list of 5 or 6 things on the board. Let’s organize these!

Jurassic, Pleistocene, Precambrian. The named times in Earth’s history might inspire mental images of dinosaurs, trilobites, or other enigmatic animals unlike anything in our modern world. Labels like ...