**Circles Minilab**

Alan L. Tobecksen Henry Clay Elementary School

13231 Burley

Chicago IL 60633

(312)535-5600

**Objectives**:

Parts of this experiment are suitable for third grade through sixth grade, but

the intended grade level is seventh through high school.

1. Students will practice measuring in the metric system.

2. Students will learn to gather and organize data.

3. Students will practice graphing simple data.

4. Students will draw the inference that the slope of the line is pi.

**Materials Needed**:

Each group of 2 to 4 students will need

6 to 10 assorted circular lids (jars, milk containers, coffee cans, etc.)

meter stick

30cm length of string

graph paper

paper to write on to organize the data

**Strategy**:

Each group measures the diameter and circumference of each lid in their

collection. The diameter is measured directly by placing the meter stick across

the center; the circumference is measured by wrapping the string around the

outside and then measuring the string. The group recorder makes note of the

data as each lid is measured. The group then makes a graph of their data

ploting diameter on the x-axis and circumference on the y-axis and, hopefully,

recognizes that the slope of the line is pi. It is also suggested that a simple

calculation of dividing the circumference by the diameter be made by the

students for each lid.

**Performance Assessment**:

**Subjective**: The teacher should observe the students to be sure that the

measurements are being done correctly and that data is being gathered and

organized.

**Objective**: The data table and graph can be given a grade.

**Conclusions**:

Students from fourth grade through high school should be able to do most, if not

all, of the exercise.

**References**:

Merrill Physics - Teacher Guide

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