Third Grade STEM Activities for Kids (223 results)

The Impossible Arrow Illusion

STEM Activity

33 reviews

Make your own 3D printed "impossible arrow" illusion in this fun activity. No matter how many times you spin the arrow around, it always seems to point in the same direction—but its reflection in a mirror points the other way! How does it work? Try it and find out! Read more

The Trick to Beating a Carnival Game

STEM Activity

16 reviews

Have you ever played a game at a carnival, trying to win a stuffed animal or other prize? It might look easy, until you try it. Why are those "simple" games at the fairs and carnivals so hard? Is it really lack of skill or coordination or do those concessionaires use some basic laws of science to help them set up the games in their favor? In this science activity, you will investigate how physics can help you win — or lose — at the classic game of trying to knock over a pyramid of… Read more

Train Wheel Science

STEM Activity

28 reviews

Have you ever watched a train roll by? If so, you might have wondered how the train is able to stay on its tracks. The secret lies in the train's wheels. Although they seem cylindrical at first glance, when looking more closely you will notice that they have a slightly semi-conical shape. (Of course, never get close to a working train!) This special geometry is what keeps trains on the tracks. In this activity you will put different wheel shapes to the test to find out why the conical wheel is… Read more

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Make String from Algae

STEM Activity

215 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

Use a Drop of Water as Magnifying Glass

STEM Activity

14 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

Worm Observation

STEM Activity

29 reviews

Earthworms are important for the soil and a lot of fun to study. Few people know there are over 2,000 types of earthworms. Some like to burrow deep in the soil, while others stay near the surface. Do you know what they eat, or what their eating and burrowing habits are? Fill a pot with moist dirt, add a few worms, and observe your worms to find out. Read more

A Magnifying Discovery

STEM Activity

7 reviews

Have you ever looked through a magnifying lens? Why does an object look different when you look at it through the magnifying lens? Even though the object appears to get larger or smaller, it really stays the same size. Each lens has its own unique power of magnification; how powerful is your lens? Read more

A Sweet Earthquake Shake on Landfill

STEM Activity

8 reviews

Have you ever thought about what type of ground buildings are constructed on? Rock, gravel, sand, soil and many others—there are lots of different types of "ground." And this issue becomes especially important in areas that are likely to get earthquakes. In this activity you will build a sweet building on a homemade shake table and find out how an earthquake impacts buildings constructed on landfill. How will your structure perform in a pretend earthquake? Read more

Best Wand for Big Bubbles

STEM Activity

5 reviews

Have you ever tried to blow a bubble, and no matter how hard you try, the bubble just will not form? Why does this happen? Why do bubbles form at all, and why is it harder to blow bubbles sometimes? In this activity, we will explore the limits of how big our bubbles can get! Read more

Build a Bathtub Toy Raft Powered by Surface Tension

STEM Activity

11 reviews

Have you ever wondered why a water strider can walk on water? Or how detergent can clean your dishes? If you look around you carefully, you can find dozens of similarly interesting phenomena that are all linked to the surface tension of water. In this science activity, you will make a little toy raft that is actually powered by surface tension, and use your vessel to investigate how surface tension works! Read more

Build a Sandcastle That Can Support a Brick

STEM Activity

11 reviews