Third Grade STEM Activities for Kids (223 results)

STEM Activity

122 reviews

Have you ever enjoyed watching something lift off into the air, like fireworks at a show or a spacecraft launching? It can be an amazing experience. It is thrilling to see something lift off against Earth's gravity. To launch a spacecraft, its rockets give it a strong push that is due to a chemical reaction. This means that every time you see a spacecraft launch, you are watching chemistry at work. In this activity you will get to blast an object into the air using two simple… Read more

Build a Bristlebot, a Tiny Toothbrush Robot

STEM Activity

173 reviews

Do you think you could build a robot on the head of a toothbrush? Bristlebots are simple, tiny robots that buzz around like bugs. They are easy to build and fun to play with, and you do not need any previous experience with robotics to make one. You can even build two bristlebots and race them against each other! Move on to the Materials section to see what parts you need to build bristlebots, and the instructions for step-by-step directions on how to build them. Read more

Oobleck: A Recipe for a Mesmerizing Mixture

STEM Activity

164 reviews

Have you ever wondered what whipped cream, jelly, and milk have in common? Aside from all being tasty, they are also all made up of tiny particles that are dispersed, or distributed, in water. This type of mixture is called a heterogeneous mixture. Some of these have very interesting physical properties, such as acting like a solid and a liquid at the same time! In this activity, you will get to create Oobleck, a mixture that is made using cornstarch and water, and then explore these… Read more

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Make String from Algae

STEM Activity

210 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

Build A Wall Marble Run

STEM Activity

139 reviews

In this activity, you will use recyclable materials to make your own wall marble run. A marble run is a fun toy and a great way to learn about physics concepts like kinetic and potential energy. Do you think your marble will make it to the end of the track? Read more

Grow Rock Candy Crystals

STEM Activity

191 reviews

Did you know you can grow your own lollipop? In this activity, you'll learn how to grow your very own rock candy. It is an easy process and not labor-intensive. So, what are you waiting for? See how large you can grow your sugar crystals before temptation takes over. Read more

How Do We Breathe?

STEM Activity

169 reviews

We breathe a lot—roughly 12 to 16 times a minute for adults and even more for children! Have you ever wondered how the process of breathing works so smoothly? Our lungs allow us to inhale the oxygen our body needs, but they do much, much more. They also allow us to get rid of carbon dioxide, the waste product created in the body, and they play a vital role in singing, shouting and even giggling. In this activity you will make a model of a lung and use it to discover how air flows in… Read more

Making Homemade Bath Bombs

STEM Activity

90 reviews

Have you ever had a refreshing bath using a bath bomb? It can be quite the relaxing experience, especially if your bath bomb has a nice fragrance or includes some bath salts. Have you ever wondered what causes a bath bomb to become so fizzy when it touches the water in the bathtub? It is due to a chemical reaction taking place between different ingredients within the bath bomb. In this activity, you will get to make your own homemade bath bombs and explore how changing the amounts of the… Read more

Measure Up with a Homemade Thermometer

STEM Activity

242 reviews

Are you eager to understand how everyday items work, or interested in making useful objects and instruments yourself? Have you ever imagined you could build your own thermometer? In this activity, you will make a liquid thermometer to track how temperatures vary with location, indoors or outdoors. What will turn out to be the hottest spot in your home? What about the coolest? Your very own homemade thermometer will be able to tell you! Read more

How to Make a Homopolar Motor

STEM Activity

225 reviews

What do you need to make a motor? Not much! In this quick activity, you will make a simple motor using nothing but a battery, magnet, and a piece of wire. Read more

Make a Whirlybird from Paper

STEM Activity

96 reviews

Have you ever seen a helicopter flying through the air? Have you ever wondered how they fly—or if you could try flying one yourself? This fun activity will help you get started at home building a simple paper helicopter. And you will learn a little bit about what keeps these amazing vehicles aloft. Read more

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