# Experimenting with Decomposition

The best learning opportunities happen naturally and are often unplanned so you have to keep your mind open and ready for those moments. Our pumpkin story is one example of how observing natural phenomena can turn into a scientific experiment.

Shortly after Halloween we noticed that the pumpkin we carved was already mushy and gross. I tried to move the pumpkin, but the bottom fell out and the whole thing was soft. We decided to move it into our backyard where we had some open space, hoping that after it fully decomposed new pumpkins would grow later in the year. After we got all the mushy pieces in the backyard, we returned to the front and noticed that the other pumpkins we had were still perfectly fine– no sign of decomposition. This is how our experiment was born!

The experiment started with this question–“Why did one pumpkin decompose, but the others didn’t?”  (Step 1 of the Scientific Method: Question)

We observed the other pumpkins and compared it to our mushy, rotting one and we noticed that the difference between them was that one was cut and the others weren’t. That helped us generate our hypothesis: Hypothesis: Cutting open a pumpkin increases the rate of decomposition. (Step 2 of the Scientific Method: Hypothesis)

It was time to test out theory! We had three left over pumpkins that had not been cut open at all. We decided to use them for our experiment. (Step 3 of the Scientific Method: Experiment)

My son suggested that we cut open a pumpkin and see how fast it decomposed. So, Pumpkin A, was cut open completely in half. I mentioned to him that in order to tell if really decomposed faster, we need something to compare it to. So in order to be able to tell if it’s really faster we left one pumpkin untouched. But, since we had one more pumpkin I suggested to him that for the next pumpkin we just cut it open in one spot, not the whole thing (this gives us another comparison).

Pumpkin A- Cut in half

Pumpkin B-  One cut on the top

Pumpkin C- Completely untouched, no openings

After we had our pumpkins all set up I asked my son some questions: “Which pumpkin do you predict will decompose the fastest?”, “Which one will decompose the slowest?”

His prediction was that the pumpkin cut all the way open would decompose the fastest and the one uncut would decompose the slowest. He also stated that the one with one cut would decompose faster than the uncut pumpkin, but slower than the one cut in half. All of this was done with my preschooler with us too. He was watching and listening as we worked.

The following weeks we observed our pumpkins whenever we went out back. (Step 4 of the Scientific Process- Observe and Record Data)

We did not record our data because we were doing this informally, but if I were doing this as a home school lesson I could have him record his data on a chart.

After about a month or so, the pumpkin that was cut in half was clearly decomposing the fast, the pumpkin with one cut was in the middle, and the uncut pumpkin was not showing outward signs of decomposition, but when we pushed on the top of it, it was soft and easier to break open.

Here is what they looked like after a few months:

Pumpkin A-

One half of pumpkin A

The other half of Pumpkin A

Pumpkin B-

Pumpkin B

Pumpkin C-

We used this to analyze our findings. (Step 5 of the Scientific Process: Analyze) Our final analysis was that the original hypothesis was correct- that cutting open a pumpkin increases the rate of decomposition.

All three pumpkins (The pumpkin on the right, Pumpkin C, was uncut in the experiment, but when we were done, we smashed open the top as you see in the picture)

And since we had two different pumpkins that were cut open to various degrees, we also found a correlation between how much the pumpkin is cut to decomposition rate. If we wanted to extend this experiment, we could test our new theory about the relationship between the amount the pumpkin is cut open and the rate of decomposition using various pumpkins all cut open in different amount. We could even measure how much area we cut open if we wanted to formalize it.

As I mentioned before, my preschooler was with us as we did this experiment, and even kids as young as him can learn from these kind of experiments. He now has the term “decomposition” in his vocabulary and understands exactly what that means. He really enjoyed checking on the pumpkins!

Step 6 of the Scientific Method- Share Results:  The boys shared their findings with their dad and Grandpa. As they discussed what they found with their family, the question of “Why?” was asked. “Why did the pumpkin that was cut open decompose the fastest?”. They brainstormed a couple of ideas and we finally came to the realization that it was exposed to the air more. We realized that the more internal surface area of the pumpkin that was exposed to the air, the faster it decomposed. Why? Because the air sped up the growth of bacteria.

By being keenly aware of our environment, curious as to why things happen, and willing to test our ideas, a great science experiments are born!

P.S. The mushy, rotting pumpkin that started it all is almost all gone:

Can you find our pumpkin?

Looking for a fun story to read:

Too Many Pumpkins by Linda White

In this story, the main character hates pumpkins! When a truck full of pumpkins drives by and accidentally spills pumpkins all over her yard, she tries to get rid of them by burying them. Silly idea, because pumpkins grow all over her yard! It creates some good discussion starting points on decomposition and how new pumpkins grew from the old ones.

# Exploring Physics: Olympic Games

I always love to get advice from a professional in their field. Which is why I am so excited to share this post from our guest author, Staci! Staci is a mom and Cancer Biologist. With her expertise in science and experience as a mom, she shares with us how she incorporates science activities into her children’s everyday experiences.

# From our Science Mom:

“Teaching science at home can be intimidating, but it doesn’t have to be.  Children are the perfect natural scientists.  They want to know the whys and hows of everything.  You can help your little scientists explore their questions in ways that will engage their minds and encourage them to think creatively in everyday situations.

I began searching for child friendly science experiments to do at home when my son became interested in all things science.  I started out doing organized experiments with him in the kitchen, but soon discovered the best lessons were learned when he directed the topic and we investigated something he had questions about.  I spend my days working for a small biotech company as a cancer biologist and my weekends helping my children nurture and explore their natural love of science.

Is your family watching the Olympics?  My family’s favorite events are the fast ones!  Downhill skiing, bobsledding and the skeleton to name a few. Watching these events is a great springboard to discuss physics with your kids. Yes, Physics!

Kinetic energy is a  concept easily explored at home with children of all ages. Simply put- kinetic energy is the energy of motion and potential energy is the stored energy of an object. To begin, set up a ramp using any objects you have around the house.  We’ve done this with cardboard tubes, hardcover books and cutting boards.

Next, decide what you want to race down the ramp.  Toy cars or different sized balls are great choices to illustrate the concept of kinetic energy.  If you have older children, consider using legos that you can build up to change the weight of the car. Does the weight of the car matter?

Car with extra weight

Let your children experiment with the ramp and cars.  How does the speed of the car change with the starting location on the ramp?  How is the speed of objects affected with a change in the shape, size and weight of an object? What happens if you change the angle or length of the ramp? What happens if you change the material of your ramp?

If you have older children, consider making a table and charting which object travel the fastest and furthest down and away from the ramp.  Can they predict which object will be the fastest down the ramp from a new group of objects?

You and your children can learn a lot with this fun activity!  What did your family learn about kinetic energy today?”

I absolutely love these ideas! We’ve done similar things in our house and they have always been a hit!

I didn’t even realize until after I took the picture, but one of my son’s favorite books is making a cameo appearance. Couldn’t have worked out better because the book is a great supplement for kids interested in physics!

Have a physics fanatic? Check out:

Physics: Why Matter Matters! by Dan Green

# Math and Science Connections: One Watermelon Seed by Celia Barker Lottridge

#### Math: Counting up to 10, Counting by tens, Counting to 100 Science: Plants, Seeds, Ecosystems

Just a few days ago on one of our trips to the library my son really wanted the book The Watermelon Seed by Greg Pizzoli, but after searching the library’s catalog we realized the book was checked out.  That’s when we came across the book One Watermelon Seed by Celia Barker Lottridge.  He really enjoyed this new book and it was a great book to use to support math knowledge.  I’m glad we found it!

Math Connections:

Counting up to 10- The story has 2 children planting a garden. First they add 1 seed, then 2, then 3, and so on.  Underneath the text the author writes the numbers in order so they kids see each number being added on sequentially.  We pointed to each number as we read them. Since it builds and repeats, it gives a lot of practice saying each number.

Counting by tens- After the children count up to 10 and the seeds grow into a bountiful harvest, the book continues on counting the fruits and vegetables by tens. Once again, the author adds on sequentially. First you see 10, then 10 and 20, then 10, 20, 30 until they reach 100. The numbers are bright and colorful. But, even better, when they reach 80 the author clearly groups the vegetables into groups of 10. For example, when they reach 80 the main character picked eighty string beans. The illustrator clearly shows 8 groups of 10 string beans.  You can show your child how this grouping allows to quickly count. They visually see what counting by tens is all about! There is a visual connection to the skill of counting by tens.  The numbers 90 and 100 are also clearly grouped by tens.

Counting up to 100- There are like a gazillion books that count from 1 to 10. But it is always nice to find books that count higher. This book does count up to 100 however, after 10 it does not count every single number up to 100. As mentioned, it begins counting by tens after it reaches 10.  If you wanted to count the ears of the corn at the end of the book, there are 100 of them! You could have them count the corn to practice their numbers up to 100.

Teaching tip:  If you are counting the objects in the picture with your child, encourage them to point to each object as they count or if they are very young you can point and count.  One of the earliest math skills kids learn is “one to one correspondence”.  One to one correspondence is the understanding that you only count an object one time.  This takes time to learn.   Have you ever seen a child count three objects and say there are five because s/he counted two things more than once?  That child is learning one to one correspondence.  Keep practicing pointing and counting an object only one time when your child is interested and they will pick up this skill.

Science Connections
:

Seed and Plants:  When the children plant the seeds and the plants begin to grow, the illustrator shows the roots growing in the ground and the sprouts growing up.  It’s a very good visual for seeing the parts of the plant. In the book, we also see the children watering the plants and weeding the garden. This can create discussion on what plants need to live and how to care for them. You can ask the child, “Why do we weed the garden?”

Ecosystems: There are great illustrations that can spark discussion. You also see worms digging tunnels in the dirt, a bird with a worm in its mouth, bugs in the air and on the ground, etc. Encourage your child to think about how the living and non living elements help each other.

Looking for another great book that counts to 100?

*Amazon affiliate links- If you make a purchase, I receive a small portion of the sale at no extra cost to you.

1 2 3 Peas by Keith Baker is incredible!

You can count each and every pea individually. And when you are on the final page, each pea holds up its number so you can count and see each number from 1 to 100 also! This is one of my new favorite books!

Check your local library for this book. It is also available on Amazon (just click on the picture)

Another great book to try for fun: