In this cool science experiment, learn about magnetism and poles, and test magnet strength to find out if two magnets are twice as strong as one.

This project compares the strength of one, two, and three-ply toilet paper.

What is a compound microscope? Kids find out by making one of their own in this cool science fair project.

This science fair project looks one of the most important factors affecting seed germination: water. A fun and easy plant biology experiment for 3rd graders.

Observe how your brain works while it is focused on one thing, and how it works while you are distracted by another thing.

Find out whether a longer airplane will fly farther or a wider paper airplane.

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!

What do ants eat? Kids find out by observing a colony of ants in this cool zoology science fair project for 4th grade.

Free science fair project idea that examines the differences between cats and dogs. Analyze objective qualities rather than subjective ones.

Build a 3d animal cell model with this cool science fair project, which helps kids visualize and understand the function of a cell's parts and organelles.

Play with balance and simple engineering as you hurry to create a sturdy rock tower.

What animals are most popular? This project affords practice in data-collection, record-keeping and data-analysis through the investigation of this question.

In this project students experiment with making music using only glasses of water.

This science fair project idea explores how length affects the weight a bridge can hold.

In this sound experiment children listen for differences as they tap on a bag of air, a bag of water, and a wooden block held up to their ears.

In this project children practice the scientific method while playing with puffy paint.

This science fair project idea examines the reason boats are shaped and engineered.

In this popcorn experiment, students can explore how two things made out of the same material can have very different appearances and densities.

In this air pressure science experiment with a balloon and a jar, children will use heat to create a partial vacuum and suck a balloon into a jar.

In this project, you'll build a model of the earth, complete with all seven continents and four major oceans.

This project explores whether plants can live and grow when "watered" with juice, soda, or milk.

In this experiment we will be determining whether birds prefer certain colors of seed.

In this science fair project, kids observe the expansion of liquids when frozen and determine if some liquids expand more than others in the freezing process.

This project determines what category of person is most likely to be ticklish.

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.

In this science fair experiment, children demonstrate the relationship between the amount of stuff and the amount of pressure in a closed system.

This classic children's game-connecting two cups with a string-demonstrates sound's ability to travel through air vs through a solid.

Marshmallows are made of sugar, water, and air pockets. Since the marshmallow is flexible, will air pressure cause it to expand when heated in a microwave?

Kids construct a single fixed pulley system to learn how pulleys can make work easier in this cool physics and engineering science fair project idea.

This science experiment has students test whether a snail moves faster on concrete or dirt.