Is it a square or a circle? See if you can trick your friends with this zany science project!

What causes the seasons to change? Kids find out by modeling the earth's tilt using a globe, flashlight and graph paper in this cool science fair project idea.

Help your curious third grader construct a dazzling spinning wheel that will teach him about the science behind colors while providing some silly entertainment!

Demonstrate how you can make your own compass using a magnetized needle. It also allows you to compare magnetic north and geographic north.

What causes dilated pupils? Young scientists will find out by applying what they already know about changes in pupil size and making models of the pupil.

In this free science fair project, build a star clock and learn how to tell time on a clear night by observing the big dipper!

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.

Saturn is the ringed planet in our solar system, a gas giant with rings made of ice and dust. Let's make a cool scale model with an old CD and some glitter!

This science fair project idea creates cool new colorful fabric pattern designs and experiments with the mixing of colors.

Your fourth grader will be astonished to discover the significance and intricacies of his spine as he builds a model of a human vertebral column.

Take to the air with science by experimenting with helicopter seeds right in your own backyard!

This science fair project idea experiments with spinning color wheels and optical illusions.

Prove that the Earth is not flat. The objective of this science fair project is to measure the angle of the sun and calculate the circumference of the Earth.

An home science experiment for older students that teaches about the science behind heat.

We all know that the Moon has different phases, but it can be hard to figure out why. Try this activity to see how the Moon's phases really work.

Tree rings can tell the age of the tree but also information about the world. This science experiment uses tree stumps to discover new facts.

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

In this project, all you need is a protractor to learn how to use the altitude of Polaris to find latitude on Earth. Polaris is also known as the North Star.

This is a quick, easy science fair project that conveys the idea of density to upper elementary students.

Learn about the layers of the Earth and make a model! Create a earth layer book, cake, or clay diagram.

What is persistence of vision? With this hands-on science fair project idea, students will demonstrate this cool and dramatic phenomenon in their own classroom.

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.

Would your child like to learn about a hidden world? All she needs to do is open her box of markers!

In this simple circular motion experiment, you'll observe tangential velocity and learn about how acceleration and centripetal force affect an object.

Here's a fun activity that will introduce your fourth grader to the concept of frictionless motion by constructing a hovercraft.

Want to spark your third grader's interest in gardening? Help him make popsicle stick fairies to decorate an enchanting garden oasis.

In this fun science fair project, make two different scale models of our solar system using Astronomical Units and planets' relative size!

Make a wish upon a tree with this craft that also helps your child learn more about Chinese culture.

Air invisible; it doesn't make sounds; you can't pick it up and throw it. So how do we know it exists? Help your second grade scientist figure it out.

Delight your budding scientist with this cool physics magic trick and teach her some basic physics concepts while you're at it!