GROW YOUR OWN
GRADE 6
The Ecology Center
Fall Season
LESSON
OUR VAST PLANET
OF LIMITED RESOURCES
TIP: Be sure to
demonstrate
proper cutting
techniques at
each step of the
cutting process.
DESCRIPTION:
This activity introduces students to the vastness of our planet’s oceans and their importance to
all life on Earth. It also introduces to them the concept of that the resources we depend on from
land (habitable area, farmable land, and fresh water) and from the ocean (upwelling areas that
allow high biological productivity) are finite, or limited.
BACKGROUND INFORMATION:
Our world is a water planet; nearly three-fourths of the Earth’s surface is covered by ocean. Of
course, Earth also means the entire planet - which if we consider all of the planet, then most of
it is actually “earth” but if we consider only the surface of the Earth, then the ocean represents
the largest proportion. While the ocean may seem a limitless resource, only a small fraction is
considered even moderately biologically productive. Nearly all the marine resources we depend
on come from a few small regions of the total ocean.
OBJECTIVES:
Students understand that a small fraction of Earth’s surface contains the resources to support
the majority of life. Students consider the global food web and practice math in the form of
fractions.
COMMON CORE STANDARDS:
CCSS:
6.NS 1: Dividing fractions by fractions
6.SL 1: Engage effectively in a range of collaborative discussions with diverse partners
NGSCS:
LS2.A: Organisms and POPs are dependent on their environmental interactions with biotic and
abiotic things.
LS2.B: Food Webs model matter and energy transfer
LS2.C: Ecosystem characteristics vary over time
LS4.D: Changes in biodiversity influence humans’ resources and ecosystem services they rely on.
LS2.A: Ecosystem carrying capacities result from biotic and abiotic factors
LS2.C: Ecological disturbances (biological, physical, human-induced) may result in an ecosystem
that reverts to a similar original state or become completely altered.
LS4.D: Biodiversity increases with more species and decreases with extinction
NGSCS Cross-Cutting Concepts:
4. Systems and System Models: Systems may interact with other systems; they may have subsystems and be part of larger complex systems
5. Energy and Matter: Matter is conserved because atoms are conserved
7. Stability and Change: Stability might be disturbed either by sudden events or gradual changes
that accumulate over time.
© 2014 EcoCenter, Inc.
GROW YOUR OWN
GRADE 6
LESSON
PAGE 02
TIME: 40 MINUTES. QUICK FACTS INTRO (5 MINUTES), MAIN ACTIVITY (30 MINUTES),
THINK-PAIR-SHARE (5 MINUTES)
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Fall Season
MATERIALS:
·· Soft apples like red delicious or golden delicious that will cut easily
··
1 globe
··
1 apple per student pair + one for teacher
··
1 knife per student pair + one for teacher
··
1 paper towel per student pair + one for teacher
··
1 water-based marker
PREP:
·· It is a great idea to practice this particular activity before performing it!
··
On the day of the activity, make one column for “Land” and one column for “Ocean” at the
front of the room on the board where you can easily write on them.
ACTIVITY:
1. Introduce the class to some quick facts about the ocean below. Ask students to find any
facts they might think are false:
»» Most of our planet is covered by ocean.
»» About 95% of all living space on the planet (for all organisms) is located in the ocean.
»» About 85% of everything that lives on Earth lives in the ocean.
»» About 70% of the oxygen we breathe comes from the process of photosynthesis by
phytoplankton.
»» Without the ocean, the surface of our planet would freeze at night and be too hot for
most life during the day. Oceans act as heat sinks, keeping the planet from freezing.
2. Hold up an apple and explain how they’ll use this model to better understand the limited
resources available on our planet.
3. Have students clear off their desk spaces and sit side-by-side with a partner. Pass out one
apple, a knife, a paper plate, a paper towel, and a set of colored markers to each pair. Keep
an apple, knife, and paper towel for to use as demonstration.
4. Tell the students that the apple will be a model to represent the planet.
5. Assign one person to be the “land” person and one to be the “ocean” person in every group.
Have the land people start with the apple, the knife, and the paper towel to cut on.
6. Have the ocean people start with the plate and the markers. Explain that the land people
are going to make some cuts on the apple and the ocean people will make a circle graph to
represent each of those cuts.
© 2014 EcoCenter, Inc.
GROW YOUR OWN
GRADE 6
LESSON
PAGE 03
7. Explain that you will demonstrate each cut before students do it themselves, but they will
need to draw on the plates themselves. Explain that you will record all the information on
the board in the “Land” and “Ocean” columns so everybody can see.
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8. Slice One: ¼ of the planet is LAND.
Tell the “Land” students that they are going to cut the apple into 4 equal pieces by cutting
it in half through the core and cutting each of those halves in half again. Cut your apple to
demonstrate.
»» Have students cut their apples and ask them “What fractional portion of the planet does
this represent?”
»» Explain that this section of apple represents ¼ of the planet, the portion that is covered
by LAND. Show this on the globe. The other three sections represent the ¾ of the world
covered by OCEAN. Have students set those 3 pieces aside for the ocean part of the
activity.
»» Teacher writes on the board: At the top of the “Land” column, write “1/4 Land”
9. Slice Two: 1/8 of the Planet is Uninhabitable Land.
Tell the Land people they are going to cut the piece of the apple representing the land into
two equal pieces. Divide your ¼ piece, lengthwise. Hold up these slices to show students.
»» Have students cut their apples
»» Explain that this piece represents all the land on Earth that’s too dry,
too wet, too cold, too hot for people to live on. These include some
mountain tops, river basins, deserts, etc. Show some examples on
the globe.
»» Teacher writes on the board: under the “1/4 Land” add a branch
labeled “1/8 uninhabitable” as shown to the right.
Activity 9
10. Slice Three: 1/8 of the planet is Habitable Land. Explain this represents
where people can live. Show examples on the globe.
»» Teacher writes on the board: Next to “1/8 uninhabitable” write “1/8
habitable”
11. Slice Four: 1/32 of the planet is Farmable Land. Demonstrate how to
divide the 1/8 piece representing the Habitable Land into four equal
pieces as follows:
»» Students now cut. Explain this small fraction represents both the
farmable (“arable”) land that grows food for people, as well as all
the pasture and graze land that grows food for animals that then
become food for people. On the globe, point to a few examples of
existing farmable land, and of land that was farmable in the past
but has since been developed.
Activity 11
Activity 11
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GROW YOUR OWN
GRADE 6
LESSON
PAGE 04
12. Slice Five: 3/10,000 of the planet is land with drinkable water.
Take the 1/32 piece of the apple and cut the thinnest, tiniest sliver possible and hold it up.
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Fall Season
»» Students cut now.
»» Teacher explains, this tiny sliver (still too big to reflect the actual proportions) is just
a model that represents 3/10,000 of the Earth’s surface. This
represents all of our lakes, ponds, rivers, streams, reservoirs, and
underground aquifers – all of the fresh water that is accessible to
us. All life on land – every plant and animal depends on fresh water
for survival.
»» Have students be sure to not lose this very important slice…
»» Set aside the “land pieces” of apple (don’t toss the tiny slice though!)
and tell students we are now focusing on the OCEAN.
13. Slices Six and Seven: ¾ of the planet is ocean. Have partners switch so
now the other person is cutting! Call attention to the OCEAN column on
the board.
Activity 12
14. Slice Six: 1/16 of the planet is productive coastal zone. Cut as follows
»» Ask, “what kinds of things do we eat from the ocean?” [Fish, shrimp,
clams, seaweed, etc.] “Where in the ocean do you think we catch the
most fish, shrimp, or clams?” [90% of world’s fisheries are located
in these productive coastal zones]
»» Show an example on the globe–perhaps off the west coasts of
North America and Africa.
Activity 14
15. Slice Seven: 3/4000 of the planet is Upwelling Zone
Take the 1/16 piece of the apple. Cut off a very thin sliver and hold it up.
»» Explain: This tiny slice (like the drinking water slice) is a model
that represents 3/4000 of the worlds surface. It represents the
6 tremendously productive upwelling areas found within the
productive coastal zone. Explain that upwelling is a process that
brings very cold, nutrient rich water from deep down in the ocean
up to the surface. The highest productivity is here in all of the
world’s interconnected ocean. Many migrating birds and marine
mammals (seals and whales) go there.
Activity 14
»» On the globe (using a water-based marker) draw a narrow band
along the Pacific coast of North America to illustrate how small this
upwelling zone is. Mark the other five major upwelling areas on the
planet: along the central and southwest coast of Africa; the central
west coast of South America; the west coast of Australia; the west
coast of Europe (Spain and Portugal); and around Antarctica.
»» Write on the board, it should look like this by the end on the OCEAN
column:
© 2014 EcoCenter, Inc.
Activity 15
GROW YOUR OWN
GRADE 6
LESSON
PAGE 05
16. Think-Pair-Share: Ask students to think of the things that most surprised or interested
them about our Planet and have them write down at least three. (1 minute). Ask students to
discuss with their partner. (1 minute). Share as a class. Use this as an opportunity to really
emphasize the core concepts (3 minutes).
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Fall Season
DISCUSSION:
1. Have students hold up the two tiniest slices they saved. One sliver represents all our
drinkable water, necessary for all life on land. The other represents all the upwelling zones,
among the most productive places on earth.
2. Ask, “What does the comparison of these slices to the whole apple tell you about these
resources?” [They support nearly all life on the planet together. They are the places humans
come in contact with, use, and affect the most. They need to be protected]
3. “Since there is so little farmable land, we don’t want to waste apples. What are some things
we can do with our uneaten apples now?” [eat, feed to animals, compost]
TEACHER TIPS:
·· Ask students to hold up their apple slices and graphs after each step so that their partners
can check them for understanding.
··
This lesson may be simplified by grouping students in groups of 4 (dedicating 2 students to
“Land” cuts and 2 to “Ocean” cuts).
REFERENCES
“Activity 1: Apple and Ocean.” Communicating Ocean Sciences to Informal Audiences, UC
Berkeley. 2014. Web. 21 Oct 2014. <http://www.coseeca.net/files/coseeca/cosia_sess7_
apple_ocean.pdf>.
© 2014 EcoCenter, Inc.