Third Grade STEM Activities for Kids (223 results)

Exploring Enzymes

STEM Activity

126 reviews

Have you ever wondered how all the food that you eat gets digested? It is not only the acid in your stomach that breaks down your food—many little molecules in your body, called enzymes, help with that too. Enzymes are special types of proteins that speed up chemical reactions, such as the digestion of food in your stomach. In fact, there are thousands of different enzymes in your body that work around-the-clock to keep you healthy and active. In this science activity you will investigate… Read more

Make Your Drawings Float!

STEM Activity

69 reviews

Have you ever wished your drawings would come alive and the stick figures or objects on your paper could move around? What sounds impossible actually is not! In this activity, you will make your drawing move around by letting it float on water. What makes this possible is the interesting chemistry of dry erase markers. These markers are usually used to write on white boards or glass surfaces and can easily be erased to make space for more writing or drawing. It turns out that they are also… Read more

Oobleck: A Recipe for a Mesmerizing Mixture

STEM Activity

166 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

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

Protect Your 'Eggstronaut': Build an Egg-Drop Lander

STEM Activity

156 reviews

The egg-drop project is a classic and time-honored tradition in many science classes. The goal is usually to build a device that can protect an egg when dropped from a high location. This activity puts a twist on the classic project, motivated by real-world advances in space exploration. Can you build a reusable egg-drop lander that can survive repeated falls from the same height? Try this activity and find out Read more

Build a Brushbot

STEM Activity

126 reviews

Brushbots are a simple, fun type of robot that you can build out of arts and crafts materials. They are easy to build and you do not need any previous experience with robotics. You can build them yourself, build two robots with a friend and race them against each other, or even make them sumo wrestle! Go to the Materials section to see what parts you need to build a brushbot, and see the instructions for a step-by-step guide on how to build one. Read more

Candy Camouflage

STEM Activity

141 reviews

Have you ever wondered how predators, like wolves, lions, and hawks, are able to find their prey? And what can an animal do to stay off of a hunter's menu? To survive, some animals have developed specific camouflage tactics to fool their predators. One strategy some animals use is to look very similar to other animals that are poisonous or that the predator doesn't like to eat. This camouflage tactic is called mimicry. In this science activity, you will be the hungry predator and you will hunt… Read more

Dissect a Flower

STEM Activity

91 reviews

Springtime is when nature comes back to life. Trees are growing their leaves again and flowers are sprouting, displaying their beautiful colors and spreading their delightful smell. But have you ever looked at a flower in more detail? What parts do flowers consist of? Are all flowers alike? In this activity, you will find out by dissecting, or taking apart, a flower piece by piece. How many plant parts do you think you can identify? Read more

Make Your Own Stethoscope

STEM Activity

120 reviews

Have you ever wondered what happens to the heart as we exercise intensely? How does its beating change? A doctor can figure this out by using a tool called a stethoscope, which is a long, thin plastic tube that has a small disc on one end and earpieces on the other end. In this activity, you will make a homemade stethoscope and use it to measure peoples' heart rates at rest and after exercising. Read more

Model the Rock Cycle with Crayons

STEM Activity

146 reviews

Use crayons to model the rock cycle in this fun activity! You will make colorful sedimentary, metamorphic, and igneous "rocks" from crayon shavings. Read more

Build a Water Strider

STEM Activity

56 reviews

Have you ever seen a water strider (also called water bugs, pond skaters, water skippers etc.)? They are bugs that effortlessly hop around on the surface of ponds, lakes, and rivers. How do they do it without sinking? Try this project to find out! Read more

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