In this cool engineering science fair project, kids learn how to build Hero's engine: an enlightening example of Newton's third law.

Did you know your body is full of simple machines? This project looks at one of the third-class levers in the human body: your arm!

Crystals are a very special structure. In this third grade activity, your child will learn how to grow salt crystals.

How does a kazoo, the strings of a guitar, or the speaker of a radio make sound? The purpose of this science fair project is to show how vibration makes sound.

This science fair project examines how seeds hitchhike on animals and clothing.

How does frost form? How fast does it form? Do this simple science project using a plastic glass, rock salt and some water to learn about deposition.

Ever wondered how a plant drinks water? This science project will teach you how and help you create a beautiful floral display!

In this experiment you observe and determine how well your cat uses his whiskers to navigate through a maze.

How does smell affect taste? Ready your taste buds--in this project, you'll gather some test subjects and do a taste test to see how much smell affects taste.

Learn how to tell time by the sun with this cool science fair project idea that tracks how the accuracy of a sundial changes over time.

How does a flashlight work? Kids will make a complete circuit and explore how voltage contributes to brightness with this science fair project idea.

How do icicles form and what do they look like? Do this free science fair project and watch the formation of icicles occur right before your eyes.

Children will learn why and how to compost as they help with the process of filling their compost, turning it, and observing the changes that occur.

In this science fair project, students discover how sedimentary layers form as sediments like mud, silt and sand settle over time.

This study evaluates if electronic devices commonly found in most households emit radiation, and if they do, how much?

In this activity, you'll not only make your own bouncy balls at home, but your child will also learn how polymers are made.

How does a compass work? What's a magnetic field? Kids will build their own compass at home to find the answers in this great science fair project idea.

For this science fair project, kids will learn how to make a lemon battery. They can conduct this classic experiment using readily available materials.

In this science fair project, students learn how pressure can make the minerals in a rock line up in the same direction and form bands and foliation.

Make your own marshmallows and mix up some very interesting third grade chemistry lessons while you're at it!

Here is a hands-on activity to help third graders understand the four points of a compass...and how we use them to get around.

In this free science fair project, learn how to separate salt from water using heat. A great science project for elementary school kids.

Create a homemade pair of sunglasses with colored lenses to see just how light and color affect our sight! Use this fun project to practice science!

How does rust form? Kids will learn about the roles oxygen, water, and electrons play in rust chemistry in this cool science fair project idea.

This science fair project explores how osmotic pressure forces water through the root up into the plant.

Invite your third grader to do taste test science to observe how a strawberry tastes when it is paired with various condiments. The results may be surprising!

This science project uses Mohsâ Hardness Test to show kids how to compare the hardness of different types of minerals.

Try this simple activity with your child to guesstimate the age of a tree in your yard and nurture her developing math skills while you're at it!

Kids learn how to manipulate additive and subtractive colors to send secret messages with red colored filters in this cool science fair project idea.

April showers may bring May flowers, but your child can preserve the beauty of spring's bounty all year long with this simple craft project!