Fun and easy play-based STEAM activity for toddlers, preschool & kindergarten
Heavy stuff - Fun science & mathematics experiment about mass & balance
Activity summary
This is not JUST another science activity – it’s a play-based, hands-on STEAM activity. It will keep your children extra engaged & motivated, which helps them learn!
In this activity, your children will be little investigators helping Esther the explorer
to solve tricky problems and find creative answers to the question: How can small things feel heavy? And large things feel light? By doing that, they get to practice concepts like mass, balance, and more.
Activity length: 20-30 minutes
Subjects: Science, Mathematics
Adapt for your age group
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For this activity, you need only these simple supplies:
trouser hangers
small plastic bags with handles
large objects that weigh very little
small objects that weigh a lot
objects that are interesting to compare
objects that are familiar to the children
What will your children learn?
Your children will learn to:
Classifying based on size and weight.
Observing and comparing the masses of different objects together.
while practicing these concepts:
mass
balance
Instructions
Step 1: Introduce the problem with a story letter
Teacher introducing the reseach problem through the letter that arrived from Supraland
In this play-based activity, your children will lead the investigation as an investigator. When children role play as investigators, they learn so much better! Try starting with a little ‘spin’ to get into character!
Then, they can help Esther the explorer solve some tricky problems in their new role.
Before the activity, prepare your supplies and print the letter.
Pro tip:
When children play as scientists, they think like scientists. Try using “scientist jackets” to help them really get into character!
When you start the activity, introduce the research problem in the form of a letter that arrived from Supraland where Esther the explorer lives.
You might be wondering: “Why should I use a story?”
Well, when you introduce a research problem through play and imaginary characters rather than just stating cold facts, children will be extra motivated to solve the problem for their new imaginary friends. Academic research shows this results in increased engagement, better focus, and improved learning outcomes.
You can find the story for this activity below (register for free to print this & many more free activities!).
Hello scientists! It’s Esther. Greetings from Mrs Noblegas’ garden!
We decided to start tidying up after all the parties.
I packed a huge bag full of party supplies, like balloons, serviettes, and paper streamers. When the bag was close to bursting with stuff, I picked it up and easily sprinted the stairs up to the attic, and tossed the big bag to the storage cabinet.
When I returned downstairs Mrs Noblegas had only collected a small basketful of tableware and decorative stones from the garden. She was huffing and puffing as she tried to climb the stairs. Indeed, Mrs Noblegas was sweating even though the basket was so small!
I rushed to help and she handed me the basket. I almost dropped it, it was so heavy! How on earth could a basket so small be so incredibly heavy?
After the child understands the problem, it’s time for some hands-on experimenting!
When children are doing the experiment, remind them why they want to solve the problem – to help Esther the explorer.
This helps them stay engaged. If they get stuck, you can ask supporting questions like: “What do you think might help Esther the explorer to solve this problem?”
If needed, you can get more ideas for guiding questions and adaptation tips for different age groups
(register here to get free weekly activities).
Here are the basic steps for his activity:
Observe the objects sent by Esther. What do the objects look like? Pay attention especially to the size of the objects.
Classify the objects based on size.
Tip: You classify using two clear groups (large and small,) or ordering by size: from smallest to biggest.
Observe the objects some more. Pay attention to the mass of the objects. What does the object feel like? Is it light or heavy?
Choose two objects and compare them which each other: which one of them feels heavier?
You may also classify the objects based on whether they are light or heavy.
Interpret if you can reliably tell a mass of an object by just weighing it in your hands.
Discuss how you could build a device to measure which of the two objects is heavier.
Build a hanger scale. Balance the hanger on the tip of your finger and hang two plastic bags to the corners to work as scale pans.
The weighing experiments can be conducted in pairs. One of the scientists balances the hanger on the tip of their finger and the other slips the weighed objects inside the bags.
Observe: What happens to the hanger?
Interpret: What can you deduce based on how the hanger reacts to the objects?
Discuss how the hanger scale works and interpret: How can you know which of the objects is heavier? You can try to arrange the objects into a line based on weight.
Practice making a prediction by connecting your findings with the story: Why could it be that Esther’s large bag felt much lighter than Mrs Noblegas’ small basket?
You may state, that sometimes large objects feel light (their mass is small) and small objects heavy (their mass is large). We can’t always deduce how much an object weighs based just on size.
Pro tip: give children the freedom to get creative and explore their own solutions!
Remember: It’s an imaginary world. It’s more than ok if children don’t give the “correct” answers right away – give them time to practice their skills.
Academic research shows children learn best through child-led play and inquiry rather than following strict instructions or memorizing facts because play allows them to build meanings and connections in an age-appropriate way.
This perhaps unintuitive approach is also proven to keep children more engaged and improve their learning outcomes.
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Adult wrapping up a play-based activity by encouraging children to share their findings with the character they’re helping.
To encourage children to analyze and share their learnings, you can gather in a circle to report to Esther the explorer.
Again, lead with the problem the character was experiencing in the letter. Encourage sharing wild and creative solutions without correcting children if they don’t fully understand the concept.
Remember: in playful learning, we’re not leading with scientific explantions – we’re putting the problem at hand into a context that makes sense to them. We can start building meanings from there.
Scientific explanation (for adults!)
You just built your own scale! Scales are used to measure the mass of objects and are really good in showing which side of the scale is heavier than the other. This is because scales are based on gravity pulling the heavier load down further on the scale. Just like in a see-saw – if you go and sit on a see-saw with an adult that is a lot heavier than you, their side will stay down, unless they use their muscles to push themselves up.
Want to know more?
The mass of an object describes how much substance there is in that object. In spoken language, the concepts of mass and weight are often used interchangeably, even though the weight of an object is related to the gravitation of Earth (or other celestial bodies), but the mass is unchangeable. For example, an object weighs less on the Moon than it does on Earth, but its mass stays the same.
Scales are used to measure mass and weight. A traditional balance scale has two scale pans hanging on opposite ends of a lever. In this experiment, we are using the hanger as the lever and the plastic bags as the scale pans.
The hanger scale works because of gravity. Earth’s gravitational force pulls the heavier object more towards itself, so the hanger is tilted towards that side. With a scale, you can compare the weights of two objects.
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This program is incredible. The characters, the stories, the experiments are so much fun. I do not need to spend any time planning. Everything I need is given to me be Kide Science.
Elsa
Kindergarten Teacher
Super easy to plan, and the items are usually things that we already have. Planning is made very easy & the children are very motivated!
Marju
Parent
Was just observed doing one of these lessons. Principal was shocked and so was I - one of the kids with pretty severe attention issues was engaged the entire time!
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Activity length: 20-30 minutes
Subjects: Science, Mathematics
30 min lesson
Medium prep.
Easy preparation
