Third Grade STEM Activities for Kids (223 results)

STEM Activity

15 reviews

Are you ready to bend light, magnify letters, and have fun with drops of water—all while getting a glimpse into how lenses work? Lenses are the key components in eyeglasses, contact lenses, binoculars, telescopes, and magnifying glasses, just to name a few devices. With this activity, a homemade magnifying glass is only a drop away! Read more

Why Won't it Mix? Discover the Brazil Nut Effect

STEM Activity

11 reviews

Have you ever noticed that the dried fruits or nuts in your breakfast cereal are not evenly spread out inside the box, or that in a container of mixed nuts Brazil nuts gather at the top? This phenomenon is commonly called the "Brazil nut effect," and the science behind it is surprisingly complex and far-reaching. This phenomenon can be a nuisance when you want to fill silos, bags, or bins with different types of materials. It can also be used to our advantage: an avalanche airbag uses the… Read more

Write and Read Braille

STEM Activity

8 reviews

Have you ever been in an elevator and wondered what the many little dots on the buttons are for? You can also find these dots in public buildings on room number signs or on ATMs. These arrangements of dots are a special writing system for the visually impaired called braille. By feeling the dots with their fingers, people can read what is written on a sign or elevator button. Do you want to find out how to read with your fingers? This activity will show you how! Read more

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Make String from Algae

STEM Activity

225 reviews

Did you know that the seaweed you've seen in the ocean or even eaten as a snack is inspiring innovators to imagine new materials? Large brown algae, like kelp, contains polymers—long chains of molecules—that are more environmentally friendly than the ones in most plastics. These natural polymers (alginates) could eventually be used to create sustainable everyday objects. Try your hand at using a bit of chemistry to turn biodegradable polymers from algae into your own custom… Read more

Balancing Act

STEM Activity

18 reviews

What makes an object balanced? Look around you—most of the objects in the room are probably balanced and not on the verge of tipping over. If someone hands you an object and asks you to put it down, you probably know, without thinking about it too much, how to place it so it won't fall over. But what's the science behind how an object balances? Why do certain objects only balance on some sides and not others? Try this project to find out! Read more

Build a Sandcastle That Can Support a Brick

STEM Activity

11 reviews

Can you build a sandcastle that can support a brick? Try it out in this fun STEM activity! Read more

Comparing Cranberry Condiments

STEM Activity

2 reviews

Does your family have jellied cranberry sauce with Thanksgiving dinner? Jellied cranberries are thick and retain the shape of the mold in which they are placed, which might mean a turkey-shaped mold or even the shape of the can if you use a canned version. Taking a bite of jiggly jellied cranberries can be a fun addition to a delicious meal, but cranberries can also be served as a liquid-like sauce. Both versions use the same ingredients, so what makes one turn into a gelatin while the other… Read more

Curl Metals With Heat!

STEM Activity

19 reviews

Do you like gift wrapping? If you do, you have probably curled a ribbon with scissors before. Have you ever wondered why the ribbon curls when you run a scissor blade down one side of it? The answer is that when you apply pressure on the ribbon with the blade, the outer layer of the ribbon stretches and expands. This makes the outside layer of the ribbon longer than the inside layer that is pressed against the blade. As a result, the ribbon starts to curl to make up for the different lengths of… Read more

Design and 3D Print a Snowflake

STEM Activity

37 reviews

Design and 3D print your own snowflake ornament with Tinkercad in this fun winter-themed STEM activity. Read more

DIY Face Mask

STEM Activity

13 reviews

To slow the spread of COVID-19, the CDC recommends wearing a mask or cloth face covering—particularly in places where it is impossible to maintain social distancing (staying at least 6 feet away from others). This recommendation is for everyone age two or older (children under the age of two should not wear masks). Many instructions to make your own mask are available online. This activity will help you think through the process of designing and making a mask as an engineering problem.… Read more

Does Wet Hair Float or Cling?

STEM Activity

Have you ever noticed how hair moves freely when it is under the water, but clings together as soon as it emerges out of the water? Not only human hair does this; when wet dogs shake themselves after a swim, their hair clings together in strands. Try this activity to see why wet hair is far less fluffy than dry hair! Read more

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