Everything Ends

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Students will be able to record changes over time of a pumpkin decomposing.

Big Idea

Recording qualitative changes over time of a pumpkin helps students refine observational recording skills.


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 tell the students they are going to watch a short video clip about the lesson topic for today.

“Room 203 I want you to watch the video closely to observe the changes they see and be prepared to discuss the processes that might be occurring.”

Make sure you have the video clip already loaded so you do not lose valuable instruction time and also your audience’s attention.

After the video clip is over I ask, “Can anyone give me a scientific explanation of what we just observed?”

We discuss the processes we saw – first the oxidization and then the gradual decomposition. I am hoping the students will recall our bread mold, apple browning and apple composting experiments. This will be a good chance for me to see which students can recall information and relate it to a new discussion/experience.    


I use this video discussion to engage my students’ attention, elicit prior knowledge and provide the students with some appropriate vocabulary. 


45 minutes

Show the students the cover of the book Rotten Pumpkin: A Rotten Tale in 15 Voices by David Schwartz and illustrated by Dwight Kuhn.

“This book is called Rotten Pumpkin: A Rotten Tale in 15 Voices by David Schwartz and illustrated by Dwight Kuhn. Can anyone tell me something they notice about the cover of this book?”

I select one or two students to respond to this question.

“I agree with you Bryan the picture of the pumpkin does not look quite right. There is definitely something odd about it.”

“Good observation Rachel. It does look like the pumpkin might be rotting, and what is the scientific word for rotting?”

I allow the students to call out the response, “Decompose!”

“You are right. The scientific word for rot is decomposing. In this story we are going to see a pumpkin decompose.”


Now I go ahead and read the book. We comment on how Pumpkin Jack’s appearance changes over time as he decomposes and the reasons for the changes we see. We discuss the different stages as molds and fungi appear.


When the book is over I tell the students, “We are going to be working on answering the question, “How long does it take for a pumpkin to decompose and sprout?””

“Can anyone give me a prediction of about how long they think it will take for Pumpkin Jack to decompose and sprout?”

I select students who raise their hand to respond. I make a record of what the students predict in my science journal. We discuss the validity of the times given based on the timeline used in the book and the clues given to determine the time of year. For example, snow obviously shows winter, warming sun and soil showing the beginning of spring, etc.

“Now here is a tricky question for you; where do you think Pumpkin Jack would take longer to decompose - inside or outside?”

I select various students to respond to the question and when responding I ask them why they think that way.  

When our discussion is over I have the students take a seat around the edge of the rug by singing the “Edge of the Rug” song.

“Team 203 I am going to carve two pumpkins and we are going to place one in our garden and one in our classroom.”

I quickly carve two pumpkins just by cutting out some eyes, a nose and a mouth. I do not bother to cut off the top or take the seeds out as I want to increase the chances of the seeds sprouting in the spring time. While I am cutting up the pumpkins I ask the students to tell me what features I am cutting so I do not lose my audience’s attention. The pumpkin which is staying in the classroom is placed in a plastic container with some moist soil spread out on the bottom. I place a lid on the container to prevent fruit flies from infesting the classroom.

When I am done I tell the students, “Today we will record our observation of what the two Pumpkin Jack’s look like today in our science journal. We will label one Pumpkin Jack “inside” and one “outside.” Then about every two or three weeks we will check on the Pumpkin Jacks and update our journal with new observations. We will compare our observations with the book we just read to see if Pumpkin Jack decomposes in the same way as the pumpkin used in the book.”

Note - Many teachers will poke holes in the container for the inside pumpkin to allow the flow of air. I do not for two reasons. First is the fact we have a reoccurring issue with fruit flies and so we do anything we can to avoid encouraging them in the building. The other reason is the smell and the mold that the decomposing pumpkin creates. Over the years I have had asthmatics who are allergic to mold spores. Keeping the pumpkin in a closed container cuts down on both issues. It does slow down the decomposition process but that just gives us longer to observe the changes. To compensate for this I have a discussion with the students about how air flow speeds up the decomposition process. We relate it back to our oxidization process experiment using the air tight containers.   

“Does anyone have any questions?”


I send the students over to the integrated work stations one table group at a time to maintain a safe and orderly classroom. It usually sounds like this;

“Table number one go get ready to 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 the activities. After 15 minutes are up, the timer goes off and the students clean up and get ready to switch stations.  

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


At the recording station I have both Pumpkin Jacks sitting on the table. The Pumpkin Jack that will be placed outside in the garden is just sitting on a cutting board and the inside Pumpkin Jack is sitting in its container. I use the date stamp to record the date so students will have adequate time to draw their detailed observations.   

Taking Pumpkin Jack out to the garden.

Placing Pumpkin Jack in the garden.

A happy Pumpkin Jack in his new home.


In this activity the students are exploring how a particular food changes over time as it decomposes. 


At another work station the students choose an animal and write about how they help Pumpkin Jack’s decomposition process (ELA). 


At another work station the students sequence the events of pumpkin decomposition and order the pumpkins by size (math). 

Ordering pumpkins


At another work station the students are making a distorted pumpkin picture by creating a picture of a Jack-O-Lantern and then ripping apart and gluing it on black paper (abstract art – engineering).


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 and take a spot on your dot. Walking feet, go.”


Once the students are seated I tell the students, “Team 203 your exit ticket today is to tell me how long you think it will take before we begin to see changes in our pumpkins. Now your answer may be different for the inside and outside pumpkin and that is okay. remember to use a complete sentence when you give your prediction. For example, "I think it will take ___ days until we see a change for outside Pumpkin Jack and the same for inside Pumpkin Jack."

“When you have told me your prediction you may 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 prediction together.


I use this exit ticket process as a way for the students to explain what they observed from the lesson we just did. This quick assessment process allows me to see if the student is able to take information learned in one format and be able to transfer it to another format.   


In order to assess if my students have successfully understood and retained the information presented in the lesson I evaluate each student by providing them with a task the next day for morning work. For this assessment I have the students write in their science journal responding to the morning work prompt, “Describe one way in which decomposition helps the environment.”

Some students will attempt to write the answer themselves and others can have an adult act as a scribe.

For this assignment I want the students to recognize the fact that decomposition is way in which nature returns nutrients back into the soil for new plants to grow. It also ties our previous lessons information into this lesson. I am hoping the students make the connections and use their prior experiences to come up with informative answers.