Teacher: Mrs. Chantel P. Lewis
Objectives:
Lesson Plans
Grade : 5th
Time: 2 (50 minute class periods)
*The students will explore and investigate the concepts of circumference,
diameter, and radius.
*The students will explore how changing the diameter of a circle affects
its circumference.
GPS: M5G2 Student will understand the relationship of the
circumference of a circle, its diameter, and pi.
NCTM: Standards 3 and 4: Geometry & Spatial Sense and Measurement
Essential Questions:
Lesson Outline:
What is the relationship between the circumference and diameter of a
circle?
How does changing the diameter of a circle affect its circumference?
1. (Whole Group 15 minutes) - Teacher will read the story Sir
Cumference and the First Round Table, A Math Adventure by
Cindy Neuschwander. Discuss the following questions.
 How does the author use vocabulary to explain
mathematics concepts? Give two examples.
 How does the author use diagrams to explain how
geometric figures are related? Show your examples by
drawing the diagrams.
 What did you learn about circles and shapes in this story?
 What other question do you have about circles or other
shapes?
2. (Small groups of four - 15 minutes) - Find four circular objects.
Measure the distance around (circumference) and the diameter.
Record measurements in the table. Each person in the group will be
responsible for one item. Measurements will be made using yarn
and then laying the yarn against a meter stick.
Object
Circumference
in centimeters
Diameter (d) in
centimeters
3. (Small group 5 – 10 minutes) Go to the website
http://math.about.com/library/blcirclecalculator.htm.
Type in the diameter from the chart above. When
you type in the diameter, this will find the
circumference. Test your findings in the chart. Are
your measurements for the circumference the same?
Students will divide the circumference by the
diameter and discuss results within groups. This
should yield pi.
4. (Whole group 5- 10 minutes). Make predictions
about how the circumference and diameter are
related. Students will divide then circumference by
the diameter and discuss results within groups. This
should yield pi. Whole group discussion of results.
Make predictions about what will happen if you double
and triple the diameter.
5. (Whole group 10 – 15 minutes) Using GSP and a projector,
the teacher will draw a random circle. Measurements of the circumference
and diameter will be made using features of GSP. Another circle will be
constructed that will be double the diameter of the first circle to see what
happens to the circumference. Measurements will be taken and compared
to first circle. Next we will triple the diameter and see what happens to
the circumference.
6. (Whole group 10 – 15 minutes) Sharing - Each group will discuss
their group findings
7. (Individual 30 minutes – 45 minutes) Students will create an
individual short story in which they correctly draw, label, and define
the diameter, circumference, and radius of a circle.
Assessment:
Extension: Explore the circumference and diameter of all the planets.
Discuss your group findings.
Students answer questions from the story.
Students complete the chart/determine and discuss the relationship
between circumference and diameter.
Students correctly draw, label, and define diameter, circumference, and
radius of a circle in short story.
Reflecting On Teaching
Were the instructional goals
met?
Were the students engaged?
Did technology enhance this
activity?
Evidence of differentiation?
Yes, each student completed work in satisfactory
manner.
Yes particularly with finding circular objects to
measure.
Yes, it was a valuable tool in reinforcing skills and
concepts.
This lesson provided activities that met the needs of the
auditory, visual, and kinesthetic learner.
Reading of the story – auditory,visual
Measuring the objects – kinesthetic, visual
Use of GSP/online tool – Visual, kinesthetic
Class discussion – kinesthetic,auditory
*Also, the different groupings (individual, small group,
and whole group) allow for all student preferences.