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Instructional
Plan
Mathematics
Governor’s Institute 2006
(Download as
Microsoft Word Document: Instructional
Plan)
Names of Group Members:
Diana
Fesenmyer, Donna Hannick,
Patricia Markowski, Merle
Topic/Theme: Footing Around with
Circumference
Level: Geometry
Time Element: Two 45-minute periods
(includes extension activities)
NCTM Standards Addressed:
Algebra,
Geometry, Measurement
PA Math Standards Addressed:
2.3.11.A,
2.3.11.C, 2.3.8.E, 2.8.11.D, 2.9.11.B, 2.9.11.F
Math Assessment Anchors Addressed: M11.B.1, M11.B.2.2.4, M11.B.2.3.1, M11.C.1.1.1,
M11.C.1.3, M11.D.2.1.3
Objectives: Students
will:
·
Measure
circumference to the nearest 1/16th of an inch.
·
Compare
and analyze the results of the change in circumference for spheres, cylinders,
and prisms.
Instructional Strategies
and Plan:
1.
Each
student will complete the writing prompt.
A belt is placed snugly around the circumference of
the earth at the equator and is measured (approximately 24,900 miles). If the belt is increased by one foot, then
placed uniformly around the equator, predict the distance that will exist
between the earth and the belt. Will it
provide enough room for a sheet of paper, a #2 pencil, or your geometry
textbook to fit between the earth and the belt?
Be specific. Use complete
sentences.
2.
Divide
students into groups of three.
Student 1 is the recorder
Student 2 is the measurer
Student 3 is the assistant measurer
Each group measures the circumference of two
different spherical objects.
Possibilities include marbles, golf balls, ping pong balls, tennis
balls, softballs, soccer balls, and basketballs.
Note: Two
different groups should measure the same type of object, such as a golf ball,
so that the data can be corroborated for each sphere.

Data Collection Sheet

r x
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Object |
Circumference of Object |
Circumference + 1 Foot |
x (in inches) |
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3.
Each
group will record its results on a Summary Data Collection Sheet.
On this sheet teachers should only include the
actual objects measured.

Summary Data Collection Sheet
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Object |
Group Number |
x (from Data Collection
Sheet) |
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Marble |
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Golf
Ball |
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Tennis
Ball |
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Softball |
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Soccer
Ball |
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Basketball |
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4.
Within
their groups students will discuss:
·
How
do the results match your original conjectures?
(Step 1, Writing Prompt)
·
Based
on these results, would you change your original predictions about the space
between the earth and the elongated belt?
5.
Teacher/group
verifies the results algebraically.

Algebraic Verification Worksheet
C2
C1
r x
If C1 =
2πr, then C2 = 2πr + 1.
In general,
to find the circumference for the outside circle:
C2 = 2π (r + x)
Find the value of x. Convert
your answer to inches.
6.
Extensions
for Day 2
Repeat Steps 1 through 5 for cylinders, cubes,
and/or right prisms.
Materials/Resources: Spherical balls, string, calculator,
linear measuring instruments, worksheets (Data Collection Sheet, Summary Data
Collection Sheet, Algebraic Verification Worksheet)
Interdisciplinary Connections:
·
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Technology: Calculator usage
Assessment Strategies:
·
Formative Evaluation
(checking student understanding during the lesson):
Two groups will measure
and analyze the same objects.
·
Summative Evaluation (How
will it be determined that the objectives were achieved?):
1.
Students
will be able to predict what will happen if one foot of string were added to
the circumference of the earth.
(Step
4)
2.
Students
will be able to complete the Algebraic Verification Worksheet. (Step 5)
Correctives/Remediation: Teacher intervention, if necessary
Extensions/Enrichment: See Step 6 for second day activities.
Special Accommodations
(special needs students)
·
Description of the Special
Needs student selected: IEP
·
Accommodations to use with
this student:
1.
Students
will be told to measure to the closest tic-marks on the measuring device.
2.
Teacher
will circulate around the room to help with measurements.
3.
Students
will write their conclusions based on class observations, stressing why
this would occur.
4.
Teacher
will show algebraically that the common difference is approximately 1.9 inches.
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