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Pre-K through Grade 2
Grade 3 through Grade 6
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Grade Levels Grades 3 and
4
Estimated Teaching Time 20
minutes
Interdisciplinary Connections
- Understanding the concept of geometric progression in germ
division (Math)
- Role playing scenarios of poor hygiene (Theater Arts)
- Observing behavior and making decisions (Social Skills)
Objectives
Students will:
- Learn the concept of geometric progression.
- Understand the value of protecting others from a sneeze.
What Students Do
Using strips of colored paper, students will simulate how germs
divide geometrically in the respiratory tract and how germs spread
to others when sneezes are commingled in a given space.
Materials Required
- Geometric progression model (blackline
master 1.5 PDF)
- Three strips of construction paper per student, as many colors
as possible (NOTE: You could use waste cut-offs from any multicolored
paper supply.)
- PURELL® Instant Hand Sanitizer
- Optional Overhead projector
and transparency film
Advanced Preparation
- Cut three strips of construction paper for each student, 1"
X 24" in size.
- Sort the strips by color so that each student receives only
one color of construction paper.
- Duplicate blackline master
1.5 PDF, one per student, or transfer onto an overhead transparency.
Suggested Sequence
- Distribute three strips of paper, all of the same color, to
each student.
- Explain to students that each strip of paper represents one
disease-causing germ in their upper respiratory tract. Tell them
that they will be using these strips to simulate how germs divide
and how respiratory germs spread.
- At a prearranged signal — a raised finger, for example
— tell them that they are to tear all the strips of paper
in half at the same time. Each time they tear the strips in half
represents one division that the germs make in the human respiratory
tract. In the body, during an illness, this division occurs very
quickly, about every 20 minutes.
- Each time you raise your finger students should tear all their
strips of paper in half again: first they will have three germs,
then six, then 12, then 24. (Students will have to tear stacks
very quickly so they will have an enjoyable challenge.) Then,
ask them to count their “germs.”
- Ask whether they were surprised to count so many germs. Pass
out copies of blackline master 1.5 and review the geometric progression
model.
- Now have all of the students face toward the center of the room.
Ask them to gather up their “germs” and hold them
in front of their faces. Tell them to “sneeze” at
the count of three, and throw their “germs” outward,
away from their faces. Have them look at the multicolored litter
on the classroom floor and talk about how the “germs”
from different people dispersed and mingled.
- Discuss the value of protecting others from a sneeze.
- Have each student pick up “germs” around them, noting
how many colors they touched, before throwing them away.
- Introduce the concept of hand sanitizing to class. Sanitize
everyone’s hands to get rid of the “germs.”
Check for Understanding
Ask the following questions:
- What did the small squares of paper on the floor represent?
- Why were there so many of them?
- How did your color squares get mixed up with the other students’
color squares?
Extensions
Using a spray bottle, squirt water into the air over the students’
heads. Make sure they are within reach to feel the water droplets.
Explain that this is similar to what occurs when they sneeze or
cough — small droplets of saliva filled with germs spray out
of their mouths. When the germs land on other people or objects,
the germs have spread. These germs have the potential to make others
sick. This is why it is important to cover your mouth with a tissue,
elbow or shoulder when sneezing or coughing.
Words to Share
- Exponential growth
- Geometric progression
- Hand sanitizer
- Upper respiratory tract
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