Third Grade STEM Activities for Kids (223 results)

Measure the Pressure

STEM Activity

106 reviews

Have you ever seen a weather forecast on TV? If so, you might have noticed the letters "H" and "L" moving around on the weather map. They are often referred to as zones of "high pressure" (H) and "low pressure" (L). The pressure they are talking about is the atmospheric pressure. Changes in air pressure can forecast short-term changes in the weather. But how do you know if the air pressure changes, or if it is high or low? Scientists have developed an instrument called a barometer that can… Read more

Model the Distances between Planets in our Solar System

STEM Activity

103 reviews

Did you know that the Voyager 2 spacecraft took 12 years to travel from Earth to Neptune, the furthest planet in the solar system? This sounds like a really long time! Maybe not that long if you consider what distance the spacecraft had to travel to get from Earth to Neptune. In this activity, you will make a model of the planets in the solar system and specifically model their distances to scale. Will it explain why the Voyager 2 took so long? Try it and see! Read more

Model Your Blood Flow

STEM Activity

67 reviews

Why is it important to eat healthy and exercise? If you don't, you might end up with a cardiovascular disease. These diseases are conditions that affect your heart and blood vessels. The job of your cardiovascular system is to transport blood through your heart, veins, and arteries, to provide oxygen and nutrients to your body. If this blood flow doesn't work properly anymore, it can have serious consequences. In this activity, you will find out what happens to the blood flow of people that… 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

Blowing the Best Bubbles

STEM Activity

47 reviews

If you have ever tried to make bubbles using plain water, you may have seen that it does not work. This is because the surface tension of water is too high. When detergent is added to water, it lowers the surface tension so that bubbles can form. Other things can be added to this mixture, such as corn syrup or glycerin, to make a solution that is even better for creating bubbles. In this science activity, you will find out which solution creates the best bubbles! Read more

Creating Craters

STEM Activity

64 reviews

How did the Moon get its craters? What about the craters on Earth? Why do they look the way they do? Find out in this fun science activity, as you make your own craters by dropping balls into a tray of flour. Read more

Flying Helicopters on Mars

STEM Activity

72 reviews

During the Mars 2020 mission, NASA plans to explore the surface of Mars using a rover in combination with a lightweight helicopter. To be able to fly on Mars, this helicopter must be super light and have very efficient blades. If not, it will never generate enough lift to get off the ground. In this activity, you will make your own paper helicopter and test different blade designs. Will your findings be reflected in NASA's design? Try it out and see for yourself! Read more

How Well Do You Wash Your Hands?

STEM Activity

46 reviews

How well do you wash your hands? Do you just give them a quick rinse with water, or do you use soap? Do you wash the backs of your hands and in between your fingers? Good hand washing is one of the best ways to prevent the spread of germs and diseases like the flu and common cold. Try this activity to find out if there are hard-to-wash parts of your hands where germs might be hiding! Read more

Afterimages: The Colorful Tricks Eyes Play

STEM Activity

60 reviews

Have you ever wondered how visual illusions are made? When we see special effects in movies, or a magic show, we often witness illusions that challenge our ability to correctly perceive things. One way in which our eyes play tricks on us is through afterimages. Afterimages are the images you see after staring at an object for several seconds and then looking away. In this science activity, you will look at afterimages to reveal the secrets of how your eyes see color. Read more

Can You Hide in Plain Sight?

STEM Activity

25 reviews

If you could choose to be an animal, would you rather be a predator or prey? For prey animals, survival in the wild means a daily struggle to escape potential predators. Predators, on the other hand, have to work very hard to make a catch. Some prey animals have evolved clever strategies to protect or defend themselves against predators. One common strategy is camouflage. Camouflage allows animals to blend into their surroundings so predators can't see them. Will this strategy increase an… Read more

Candy Core Samples

STEM Activity

48 reviews

Act like a geologist in this fun activity as you drill "core samples" from candy bars using a straw. Can you identify the type of candy bar just from a sample? Try this activity to find out! Read more

Explore Our Science Videos

Song Recommender with Unsupervised Machine Learning and Python: A Step-By-Step Coding Tutorial

Upcycle Paper Products into Plantable Seed Paper | Science Project

Best solar panel location | micro:bit science project