This lesson Standard will help students understand that the shape of Earth and the moon are spherical and
that Earth rotates on its axis to produce the appearance of the sun and the
moon moving through the sky.
The Flat Spinning Earth
The Flat Spinning Earth on an Axis
- Ping-pong ball
- Pizza box
- Aluminum foil
- Glue stick
Sun Dagger video, by BullFrog Films(email@example.com); ISBN (DVD) 1-59458-089-8
Pop-Up Books, by Interact (Highsmith, 1-800-359-0961, Highsmith.com); Item number -
Background for Teachers
The fact that Earth is not flat is not obvious to children. It is a
sphere that is 7,926.41 miles (12,756.32 kilometers) in diameter at the
equator. One of the first ways that we suspected that Earth was round
was because we could see its shadow on the moon during an eclipse.
It would be helpful for the teacher to practice with the pencil top to
find the best length for the pencil. Longer pencils do not work as well.
In my observations it seemed best to have a pencil about 2 inches long.
Intended Learning Outcomes
1. Use science process and thinking skills.
4. Communicate effectively using science language and reasoning.
Invitation to Learn
The Flat Spinning Earth
Hand each student a washer and ask them to identify ways that
the washer and Earth are the same. Color and cut out the outline
drawings of Earth and glue them to one side of the washer. Using
a single light source, like the sun coming through the window or a
desk lamp and a playground ball or globe as a backdrop, invite them
to notice the different possibilities of shapes made by the washer and
record them in their journal. Now pass out a ping pong ball and ask
them to identify and draw as many different shapes as can be made
by the ball. Are there ways the washer makes a circular shadow? Is
it possible to make the washer continuously appear to make a circular
shadow? Instruct the students to make a Venn Diagram in their journal
comparing Earth and the moon.
When we are outside, where and when can we see the shadow of
the moon and Earth? Does this teach us about the shape of the moon
and Earth? How? Take time to answer questions about eclipses.
The Flat Spinning Earth on an Axis
- "What do you do with a pencil that is too short to reasonably
hold?" Ask the students to get the pencil that has been
sharpened to within two inches of its life.
- Insert the pencil into the hole in the washer far enough that
friction will solidly hold it in place.
- Write the word "axis" on a small piece of tape and attach it to
the pencil nearer the eraser end.
- Write the word "rotation" near the outer rim of the washer.
- Practice spinning the "Earth top". If it wobbles try to figure out
why. What makes it spin longer? Does it help if the washer
forms a right angle to the pencil all the way around?
- Discuss the axis as it relates to the map of Earth on the washer
with others at your table. Does Earth really have a pencil stuck
through it? Does Earth spin like the washer?
- Spin the ping-pong ball. Is there a place it seems to spin
around? How is the ping-pong ball like Earth? How is the
pencil in the washer like Earth?
- Set the ping-pong ball aside for use in a later activity.
- Make a pocket in your journal to store your disassembled Earth
axis (pencil) and rotation model (washer with the map).
- Demonstrate pop-up doors and a stand up. Share some of the
pop-ups the students have made.
- Invite the class to create some pop-ups in their journal.
- The rotation of Earth on its axis causes our day and night. The
orbit of Earth around the Sun measures our years. Did the
ancient Native American people have a way to keep track of the
elapsed time of years and seasons? Show Chaco Canyon Fajada
Butte Sun Dagger. Discuss that they understood about the
apparent motion of sun across the sky and used it to measure
lapsed time. Show an analemma and discuss how it shows
lapsed time. Answer questions and ask if it could be used to
show more than days and months. Could we expand it to
show time of day, make it a sundial? Show and discuss the San
Francisco "sundial". For your class it all begins with a small
empty pizza box, some aluminum foil, paper, tape and a fine
tipped marker or pen. Make a classroom solar calendar.
- A block of wood with a three eighths diameter hole three
inches deep will help the challenged learner get the right angle
between the axis (pencil) and the rotation (washer).
- Art: Earth on its axis model could be a colored pencil and then
spun on a piece of black construction paper to add to other
designs for fireworks display or to trace spiral type designs on
- Send a washer home with the student and a map to apply to the
washer. With a note asking the parents to allow the student to
review what they learned.
- Invite parents to help the student notice other places in life
where there is an axis (like an axel on a wheel) and something
rotates around it (the tire).
- Prior to the lesson, as pre-assessment, spin a globe of Earth and
ask "Is there some part of the globe where the spinning part is
the smallest? Why do you think that happens?" (It is closest to
the center of the spin, 'rotation'). We call the center of the spin,
axis. The part that goes around rotation.
- At random times during the year, after this activity, when the
students are using their pencil for work, hold up a pencil and a
washer and ask "When they are together the way we used them
in Science what names did we give them?"
- Spin a ball during PE and then ask "What is the ball doing that
is like Earth?" "Where is the axis?"
Furner, J. M., Yahya, N., and Duffy, M. L., (2005). 20 Ways to teach mathematics: Strategies
to reach all students. Intervention in school and clinic,. Volume41, No. 1 (September
2005), Pages 15 -23.
Even though this article is written with different approaches to
teaching mathematics, the hands-on activities, heterogeneous grouping,
charts, auditory, visual and kinesthetic approaches work well in nearly
any setting or grouping. It is just good teaching.