Eww.. Germs!

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Students will be able to explain why it is important to wash our hands based on the results of our investigation.

Big Idea

Investigating how quickly mold grows on bread helps students understand the importance of washing your hands.


10 minutes

Gather students on the rug using a preferred classroom management technique. I like to use my “Stop, look, listen.” The students stop what they are doing, look at me and listen for the direction. I usually preface the direction with, “When I say go…” This reminds the students to listen to the whole direction before moving to follow the directive.

In this case I would say, “When I say go I would like you to clear your space, push in your chair and go take a spot on your dot. Walking feet go.”

By saying “walking feet” I am reminding the students to use walking feet in the classroom to ensure safe movement between areas.

When all of the students are seated on their dot in the rug area I ask them, “Who can tell me what a germ is?”

I select a student who is following the correct classroom protocol of raising their hand to respond to the question.

“Nice answer Harper; a germ is something that can make you sick.”

“Who knows how germs are spread?”

Again I select a student who is following the correct classroom procedure of raising their hand.

“Good answer Max; one way germs are spread is when people do not wash their hands.”

“Sometimes when you look at your hands they look clean and you think they don’t need washing but really they do. Germs are so tiny that you cannot see them by just using your eyes.”

“I have an image of bacteria, which is a type of germ, for you to see moving under a microscope.”

I use the SMARTBoard to show my students a brief one minute clip of bacteria moving under a microscope.

Once the short clip is over I tell the students, “Germs are so small yet they can do lots of damage if they are left to spread.

“Now I am going to read you a book about germs.”


I use this brief discussion to engage my students. Through this discussion they will begin thinking about germs and how they spread. The students may begin to access prior knowledge or generate questions about how germs spread from one place to another. 


45 minutes

“This book is called Germs Are Not for Sharing. It is written by Elizabeth Verdick and illustrated by Marieka Heinlen.”

As we read through the book I ask the students questions relating to the text. For example, “How do you think the germs get on your pets?” “Does this mean you should never touch your pets?” “Why or why not?”

I use the fair sticks to select different students to respond to the questions.

You will need to gauge your audience’s attention span and interest level to determine how many questions you ask and the length of discussions you have. 


Teaching Challenge - How do I teach my students how to plan an investigation? 

At first I use questioning and modeling.  

When the book is over I ask the students to take a seat around the edge of the rug by singing the “Edge of the Rug” song.

Once everyone is seated in a u around the edge of the rug I sit at the open end and place three pieces of brown bread on a tray in front of me (I use brown bread because it has less preservatives than white bread). I also have a container of dirt, a few paper towels, a set of tongs, three Ziploc bags, a permanent marker and a plant mister.

“Room 203 I have three pieces of bread in front of me which are going to help us see just how powerful germs can be.”

“First I am going to need two volunteers to get their hands dirty.”

I usually have many students who want to get their hands dirty so I use the fair sticks to determine who will be our volunteers today.

“Now I want my two volunteers to rub their hands in the container of dirt. Why do you think I want them to put their hands in the dirt?”

I select two or three students to respond to the prompt. “Those were all good ideas. I do want them to get germs on their hands. Now I want Adam to go and wash his hands at the sink. I want Rachel to use these paper towels just to wipe off all of the dirt off her hands.”

To maintain my audience’s attention while the two students are following the directions I gave them, I ask, “Whose hands do you think will be cleaner?” and “Why?”

Once the two students have completed their task I give each one a slice of bread and ask them to rub their hands on both sides of the bread.

When they have finished rubbing their hands all over the bread I have them place each of their slices in separate Ziploc bags.

Now I ask the students, “What do you think I should label the bags with so we know which slice of bread is which?”

Many of the students think we should label the bags with the student names. I accept that but I add, “Well I also want to remember what each student did so I am going to put “washed” under Adam’s name and “wiped” under Rachel’s name. This way if a stranger comes into our room, they will be able to check on our experiment and know what we did to each piece of bread.”

“What do you think I am going to use this last piece of bread for?”

Many of the students will think it is for another student to use, or me. This is because they have not learned about a “control” yet and this is where I am going to explain to them what a “control” is.

“Those were all good suggestions. This piece of bread is called a “control.” My “control” is here to help me see the difference between what would normally happen and what I did to change the situation. This piece of bread has not been touched by any hands at all. I am going to use the tongs to place it into the Ziploc bag. What should I label this bag?”

Most students will call it control and I add, “What if a stranger comes in?”

“That’s right we need to also add “untouched” so they know no one touched this piece of bread.”

“Now I need one more volunteer to mist our bread with water so there is a little bit of moisture in the bag.”

Once again I use the fair sticks.

While the selected student is misting the bread I tell the students, “The moisture will help any bacteria grow just like water helps a seed to grow.”

“Now our bags are ready. Now because we want to test only what happens when you touch bread with washed and unwashed hands we must hang the bags all in the same place. We are going to need to hang our bags in a cool dark place. Who has a suggestion where we can do that?”

I take two or three responses.

“I think we will go with Wesley’s idea of hanging them under the sink area. It is a cool dark place and one we can easily check how experiment is doing without too much interference.”

“Let’s all walk over and see the place.”

While the students are standing there I use duct tape to stick the bags to the wall under the sink area.

Once the bags are stuck there I tell the students to go back and take a spot on their dot by singing the “Spot on Your Dot” song.  

Our germ bread experiment.


After the students are seated I tell the students, “At one of your work stations today you will record what you see today in the Ziploc bags. Now remember you need to draw exactly what you see so others will understand you are trying to answer the question, “Which piece of bread will grow the most mold first?” Answering this question will help us to answer the main question which is, “Why is it important to wash our hands?””

“While you are working I am going to give you a strip of paper which explains what we did so you will have a record of how we began our experiment. You will glue this on the page next to your recording page.”


Once I feel the group has a good grasp of the instructions I send the students over one table group at a time to maintain a safe and orderly classroom. It usually sounds like this;

“Table number one go have some recording fun.

Table number two, you know what to do.

Table number three, hope you were listening to me, and

Table number four, you shouldn’t be here anymore.”


Allow the students 15 minutes to work on this activity.

I set the time on the visual timer and remind the students to look at the timer so they will use their time wisely.

Student working on his recording of the germ bread experiment.

Student example of recording. Observation plus labeling.                  Another student recording.

Our Germ Bacteria Experiment Explanation Sheet - I cut the top part of the sheet and glue it to the left page of the students science journal. Their recording goes on the right side. We check the experiment every 3 to 5 days (depends on weekends etc) and the students draw what they observe. At the end of the experiment (this can take a few weeks), I glue the bottom part of the sheet into the students' science journal and have them draw what they observe and answer the questions.  


In this activity the students are exploring one way to plan and carry out an investigation which will help them answer the question; “Why is it important to wash your hands?” The students were modeled the process of setting up an experiment which changed just one thing; which was the type of hands used to touch the bread. They were shown that an experiment should have a control so they can investigate the results accurately.

Students need to be modeled the experimental process so they can develop the skill for themselves. Setting up accurate and effective experiments is a skill the students will need to develop so that they are able to test their own hypotheses.    


At one of the stations the students are introduced to Bob the Sock.

Introducing Bob the Sock

For this activity you will need an old sock with a face drawn on it, black paper, a black ball point pen and a mixture of talcum powder and glitter (I like to use gold or silver as these colors stand out against the black paper better).

I have the students come over to the big table in my classroom. The smaller students I have sit in chairs while the taller students stand behind them. I direct the students’ attention to the black paper which I have already laid down on the table. “This black paper will help us to see the “germs” which Bob and I are about to show you.”

I place the sock puppet on my hand and give him a very stuffy voice. “Hi, my name is Bob and I have germs cause I have a cold. I like to share my germs ‘cause I have no manners. Want to see me share my germs?”

The students are usually pretty excited and curious by this and are dying to see Bob share his germs. While the students are watching I put a small handful of the glitter/powder mixture into the sock puppets mouth. Now I ask Bob “Are you ready to show the students how you like to share?” Bob nods his head vigorously. “Okay. Everybody pretend you are going to sneeze and then Bob can sneeze with us. Ready? Ah, Ah, Ah choo!”

At this point I open the socket puppets mouth with a slight flick and the glitter/powder mixture shoots out across the black paper on the table. The students usually jump back a little in surprise but laugh when they see all of the glitter and powder spread across the paper.

Now I ask if there is a volunteer who is willing to touch the “germs” on the table. There are usually plenty of student volunteers so I use the fair sticks to select a student.

 I ask that person to reach out and place their hand on the black paper like they were leaning over to get something on the other side of the table. “Now Jo, hold up your hand for us all to see.” There is usually quite a bit of powder and glitter on it. 

Next I ask that student to take the pencil I am offering them and then pass the pencil to a friend.

Reaching for a "germ" covered pen.                            Using a "germ" covered pen.

“Now Bryan, you hold up your hand for us all to see.” There is usually a little of the mixture.

I ask that student to pass the pencil to one more friend. “Now Sebastian, you hold up your hand.” There is a tiny amount on this hand.

“Boys and girls what do you think will happen if I tell everyone it is snack time and one of these students’ does not wash their hands?”

“Your right; they will get some of the germs on their food and then the food will go into their system and they will get sick.”

This lesson is a very good way to give the students an excellent visual on how easy it is for germs to spread in the classroom.

At this point in the lesson I ask the students to focus their attention back onto Bob as he is going to show them the correct way to cough or sneeze. First I ask them, “What do you think will happen if I sneeze into my hand?” Most students will be able to tell you the germs will spread because you will touch things. If time allows I give a brief demonstration.

I tell the students, “Watch what happens when I have Bob sneeze the correct way into my elbow.” I repeat the procedure I used above where the students acted out sneezing along with Bob. This time he sneezes into my elbow. “Do I touch anything with my elbow?”

“No, you’re right I do not. Here is a simple rhyme to remember how to cough or sneeze into your elbow.”

“Pretend you are a super hero with a cape and you are masking your identity from the public so you pull your cape across the front of your body to cover your face.”

“Now repeat after me;

Be an awesome super hero,

Cut germ spreading down to zero.”

We practice it a couple of times.

Practicing how to be a hero and cutting germ spreading down to zero.

Boys practice too. 


At another station the students go with the school nurse to learn the proper method of hand washing in the bigger roomier bathrooms.

 First she sprinkles each student’s hands with a different colored glitter and has them shake hands with each other. This way the students get to see just how many germs are spread just through shaking hands.

Next she uses special smelly soaps (fruit smelling soaps and seasonal soaps work really well) to make washing your hands exciting while teaching them the step by step procedure we use here at school. 



At the art/engineering station the students make a germ painting. We do this by looking at a variety of different germ pictures on the SMARTBoard. Next we use three different colors of paint and place a spoonful of each in the center of a large piece of paper. The students’ then fold the paper in half and rub it all over on one side. When they have finished rubbing we open the paper and sprinkle a little glitter on it. Once the painting is dry we cut around the edges and it looks like a “germ.” We place our “germs” up on our bulletin board with the title “Our Germs Will Not Spread.” 

Germ painting example



These activities provide the students with the opportunity to apply and expand their understanding of the concepts within new contexts and situations thus elaborating on the information they have been presented with. 


10 minutes

When the time is up I blow two short blasts on my whistle and use the “Stop, look, listen” technique mentioned above.

“When I say go, I would like you to clean up your space remembering to take care of our things, push in your chair, place your work in the correct bin and use walking feet to take a spot on your dot. Walking feet, go.”

Students know to place their work in either the “finished work” bin or the “under construction” bin. Work in the “under construction” bin can be completed later in the day when the student finds they have spare time to fill in.


Once the students are seated on their spot on the rug I tell them that their exit ticket for today is to share with the class one way we can stop the spread of germs both here in the classroom and at home.


“For today’s exit ticket you need to share with us one way you can stop the spread of germs. When you have shared a germ stopping method with us you can use the hand sanitizer and get your snack.”

I use the fair sticks to determine the order of the students.

If a student is unable to give me an answer, they know they can do one of two things.

  1. They can ask a friend to help, or
  2. They can wait until everyone else has gone and then we will work on a method together.

I use this exit ticket process as a way for the students to communicate one of the pieces of information they learned by explaining to me one way they can stop the spreading of germs. Through this explanation process I can see who is able to obtain information and retain the information learned on a given topic.


Later in the day we watch Washing Hands from the Brain Pop Jr. website to reinforce the lesson we had in the morning. 



10 minutes

In order to assess if my students have successfully understood and retained the information presented in the lesson I set out an evaluation task for morning work the next day.

As the students arrive I have the task laid out at their place on the table.

The students will need to sequence the steps for effective hand washing.

Hand washing sequence steps - this I have cut up and out of order at the table

Hand washing sequence recording sheet

Once the student has sequenced the steps they are to bring their work over to me to check. While I am checking their work I have the student explain to me why it is important for us to wash our hands.

Next I will have the student tell me two different situations where it is important to wash our hands.

As the student explains to me the why and the when of hand washing, I will write their responses under the sequencing they did in their science journal. This provides a quick anecdotal record for me of whether or not the student is able to retain information presented in previous lessons and transfer the information to a new task.

Recalling the information this way reinforces the previous day’s lesson and aids in student comprehension of the topic.


We will continue to check on our bread over the next few days to see which piece grows the most molds first.

We will record the results in our science journals.

Based on our investigation the students should see evidence which will support the importance of washing our hands before we touch food.   

After two weeks I will have the students come to me during a time when I can meet with them one-on-one; such as during free choice center time.

I will ask the students based on our class investigation, “Why is it important to wash our hands?” and also, “How do you know?” I will record their responses on camera so that I have a record of evidence of learning. I record the student responses because many kindergarten students cannot write detailed responses and I do not want them to limit their response based on their writing ability.