Third Grade STEM Activities for Kids (223 results)

Make a Homemade Fly Trap

STEM Activity

64 reviews

Have some pesky flies in your kitchen that you cannot seem to get rid of? In this project you will build your own simple fly trap from a plastic bottle. Get ready to get rid of those flies! Read more

Milk Curdling with Enzymes!

STEM Activity

43 reviews

Have you ever gone to pour yourself a cup of milk, and all you get is clumps? What happened to the milk is called coagulation, which is the mechanism that occurs when proteins in the milk clump together. While you do not necessarily want this in your milk, without coagulation (or curdling), there would be no cheese or yogurt, which is why it is a very important process in the food industry. Wonder how you can make milk curdle? Do this activity to find out! Read more

Model the Solar System with Marbles

STEM Activity

61 reviews

What would it be like if you could see the planets of our solar system orbiting the Sun all at once? What about the moons orbiting the planets? Learn how to make your own simple demonstration of gravity and planetary orbits in this fun activity. Read more

Featured

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

Musical Bottles

STEM Activity

22 reviews

Have you ever blown across a bottle's top and made a pleasant, resonant sound? If so, have you wondered how that note is made exactly? The exact note you hear depends on the resonant frequency of the air in the bottle. Musical instruments like ocarinas operate based on a similar principle. In this science activity, you will use bottles to investigate how the volume of the air in the bottle affects the pitch of the note that it makes. Read more

The Ambiguous Cylinder Illusion

STEM Activity

22 reviews

Is it a circle? Is it a square? Or is it both? Make your own 3D printed "ambiguous cylinder" illusion in this fun activity. Read more

The Bouba-Kiki Effect

STEM Activity

20 reviews

If you had to name some shapes "Bouba" and others "Kiki," which name would you give a pointy shape? How about a rounded shape? Would your friends have the same answers? In this activity, you will investigate the Bouba-Kiki effect to learn more about the human brain's fascinating connection between shapes and sounds. Read more

What Are the Chances?

STEM Activity

46 reviews

Have you ever heard anyone say the chance of something happening is "50-50"? What does that actually mean? This phrase has something to do with probability. Probability tells you how likely it is that an event will occur. This means that for certain events you can actually calculate how likely it is that they will happen. In this activity, you will do these calculations and then test if your calculations hold true for reality! 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

3D Print with Icing: No 3D Printer Required!

STEM Activity

8 reviews

Are you wondering how a 3D printer works? In this fun activity, you will be the printer and make colorful 3D prints using royal icing. No 3D printer is required, and your prints are edible! 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

Explore Our Science Videos

DIY Jumping Robot: Fun Engineering Project

Comparing Different Types of Irrigation Systems | Science Project

Model Your Blood Flow – STEM activity