1. Topic-
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2. Content-
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Seasons result from annual variations in the intensity of sunlight
and length of day due to the tilt of the axis of the Earth relative
to the plane of its yearly orbit around the sun. Key words: orbit,
revolution, rotational axis |
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3. Goals: Aims/Outcomes-
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1. At the end of this lesson, the students will know why we have
seasons.
2. Students will know what each season is.
3. Students will know how the earth moves around the sun. |
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4. Objectives-
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At the end of this lesson, students will be able to:
1. Identify the names of each of the four seasons.
2. Demonstrate with a partner how the sun moves (rotation and revolution)
in the solar system.
3. Tell how the angle of the earth determines the seasons. |
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5. Materials and Aids-
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>Collection of seasonal objects and pictures
>Construction paper in light colors
>Crayons or colored pencils
>Beach ball, or other large round object
>Modeling clay - enough for each pair of students to have a small
amount (to make a 1/2 inch ball)
>Oranges - enough for each pair of students to have one
>Toothpicks - box of 100 (several toothpicks needed for each pair
of students)
>Whiteboard and markers (or use a chalkboard, smart board, projector,
etc.)
>Earth cross-section model (or use a ball with a line drawn around
the middle to show the equator, and a globe to show north and south
poles) |
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6. Procedures/Methods-
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A. Introduction-
1. Collect a variety of seasonal objects and pictures that show
the four different seasons.
2. Divide the objects into even piles - with one pile for each small
group (3-4 students) in the class. Each pile can be put in a box,
basket, or bag. Each pile should have between 10-20 objects such as
magazine pictures (beach scenes, snow scenes), fake fall leaves, winter
hat, gloves, flower seeds, etc.
3. Have the class split into groups and give each group a pile of
objects to sort. Tell them there are many ways to sort the objects,
and they must decide as a group how to sort them.
4. After each group is finished, talk with the class about the different
ways the objects were sorted. Did any group choose to sort their items
by the four seasons? Explain that they will be learning more about
what each season is and why we have seasons. |
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B. Development-
1. Write the word 'winter' on the board, and have students come
up with words to describe it. Do the same for 'summer,' and then for
spring and fall.
2. Once there is a list of words describing each season, hand out
pieces of construction paper to each student. Each student should
choose a season, and draw a picture of what the weather looks like,
using crayons or colored pencils.
3. After they have finished their picture, have the students turn
the construction paper over and write 2-3 sentences about the season
they chose. Remind them to use descriptive words, like those written
on the board. |
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C. Practice-
1. Using the cross-section model of the earth, point out the equator
line and the north and south poles. Tell the class that we live closer
to the North Pole (you may wish to pass the ball around and let students
find North America for themselves).
2. Explain that Earth spins around in a circle (called rotation) while
making a path (also called an orbit) around the sun. One complete
orbit around the sun is called a revolution. One revolution is a year.
One rotation is a day.
3. Display the worksheet on a projector screen so everyone can see
it. Explain that the earth actually revolves around the sun at a tilt,
or angle. This is called its rotational axis.
4. Hold the foam model; point out the equator again, then tilt the
model so that it is at an angle (meaning the North Pole does not point
straight up).
5. Ask for a volunteer to come up and hold the beach ball. Explain
that the beach ball represents the sun and the foam model is the earth.
Still holding the foam model at an angle, slowly walk around the sun,
completing one revolution. How does the rotational axis determine
the seasons? When the North Pole is tilted away from the sun, it is
winter in North America. When the South Pole is tilted away from the
sun, it is summer! The in-between seasons (spring and fall) are when
the earth gets just about the same amount of sunlight on the south
and north poles. When it is summer on one part of the globe, it is
winter on the other part. The equator is always the warmest part on
earth because it is closest to the sun no matter what the angle of
the earth is.
6. After you verbally explain the reason we have seasons, hand out
a worksheet for each child to color in (coloring can be done in class
or at home, depending on the time that is available). |
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D. Independent Practice-
1. Remind students how it looked when you held the earth model and
walked around making a single revolution. Tell students that the sun
always rotates while it is revolving.
2. Take a small piece of clay (about half an inch in diameter) and
insert a toothpick in the center, so you can spin it between your
fingers. Spinning in a circle like this is what the earth is doing
constantly! In order to make one rotation a day, the earth must move
at speeds of 1,000 mph, while at the same time travel through space
(orbiting the sun) at speeds of 67,000 mph.
3. Have students get into pairs and give each pair a piece of modeling
clay, a few toothpicks, and an orange. Let them experience how the
clay model of the earth is able to move around the orange (the sun)
up close.
4. Walk around making sure that each group understands that the earth
moves at an angle, and they hold their toothpicks at an angle instead
of straight up and down. If students understand this concept well,
you may have them also spin the orange slowly, since our sun does
rotate (though not at the same speed of Earth).
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E. Accommodations (Differentiated Instruction)-
1. If students struggle with writing, they can have the teacher
write their words for them as they dictate.
2. There are a variety of visual and auditory cues meant to build
learning in this lesson.
3. If a student cannot see the board or the foam model of the earth,
invite them to move closer.
4. If a student has auditory discrimination problems, invite him or
her to sit closer to the front, or have this student work with a partner
who can repeat something the student may have missed the first time. |
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F. Checking for understanding-
1. When students are finished creating their clay-and-orange model
of the earth's movement around the sun, have each student get out
their drawing of a season that they worked on before. On the back,
have each student write one or two more sentences about what makes
seasons and why the weather feels the way it does during the season
they chose.
2. Point out the words 'orbit,' 'revolution,' and 'rotational axis'
on the board, to help students write their sentences.
3. Each student should turn in their drawing when finished, so that
you can read what they wrote and check for understanding. |
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G. Closure-
Teacher ask students:
1. What season is it when the North Pole is tilted away from the sun
in North America?
2. Why are we in the Fall season now? |
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7. Evaluation-
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1. To extend this lesson, you can have students act out the solar
system in a large open area, such as a gym. Pick volunteers to be
the sun, moon, and earth. Remind students that the moon revolves around
the earth, which rotates as it revolves around the sun, and the sun
rotates, but only very slowly.
2. Let students take turns acting the parts of the solar system. |
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