4. My Time - Lesson Plan

Lesson Plan

  1. Begin the day with a discussion of time. How do you think about historical events? Do you categorize events by decade? Do you categorize events by major turning points in history like the American Revolution and the Civil War? How about events in your own life? Do you categorize things by what school you attended? Do you categorize things by where you lived? Do you categorize things relative to major family events like the birth of a sibling or a divorce?
  2. Today we will be organizing events like geologists do and become familiar with the format of the time scale used to organize information about Earth history.
  3. Pass out the handouts and explain the general directions described on the first page:
    • Create a list of 20 major events in your lifetime
    • Place a number beside each event according to which happened longest ago (1) and which happened most recently (20)
    • Rewrite the list in reverse chronological order, with the most recent at the top and the most long ago at the bottom
    • To the new list, add information about exactly how many years ago the event occurred
  4. The list so far is what geologists refer to as a relative or sequential timeline. This is what students created from information gathered at the Caldecott Tunnel if you did that field trip or in their summary paragraphs from the Layers Upon Layers lesson. Discuss the difference between relative time, ordering events by which happened first, and absolute time, the number of years ago each event happened. A relative timeline can be observed from rock layers just by reading it from bottom to top. But is it possible to observe the actual, absolute number of years ago a rock layer formed just by looking at it? No. You can determine absolute time for events from your own life because you can remember each event, but nobody can remember the exact, absolute age of a rock unless it’s a crayon rock or a homemade sedimentary rock. Scientists use special tools to find the absolute, number of years ago a given rock layer was formed. More on this in later lessons.
  5. After the discussion about relative and absolute time, students can categorize events into a hierarchical series of time periods. Students should think about a logical way to divide their life events into 2 categories such as “before I started school” and “after I started school” or perhaps “when I lived in New York” and “when I lived in California”. These will form the largest divisions of your personal time scale and will be called eons.
  6. Students should draw a horizontal line across the eon, era and period columns, dividing their table according to the criteria they chose. They should name the categories with a 1 word label that ends in the suffix –ian or –ic. For instance, “Preschoolian” and “Schoolian” or “Newyorkian” and “Californian”. In the eon column, they should write down the names they chose.
  7. Now students should divide each of the eons into 2 or 3 eras based on a different criteria. For instance, the “Schoolian Eon” can be divided into the “Elementarian Era” and the “Middleschoolian Era”. Students should divide their tables by drawing a line across the era and period columns according to the criteria they chose and should write in the name of the eras.
  8. Finally, students should divide each era into 2 or 3 periods, if that is possible. If an era contains only a single event, then you don’t have to divide it. Students should divide their tables by drawing a line across the period column and should write in the name of the period.
  9. If you have remaining time, students can color their tables or share them with one another in small groups.