Do you have your isopods straight? Learn about sow bug and pill bug behavior by building a terrarium to study them in!

Show your child how to construct a homemade thermometer. It's hands-on fun and a great way to learn about this important instrument!

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

In this experiment, you'll make a seafloor spreading model to learn more about how plate tectonics work and create mid-ocean ridges.

Learn about the fruit fly life cycle in this experiment. Capture fruit flies to examine various stages of insect metamorphosis.

4th graders construct an ocean food web to learn about consumers and trophic levels, food webs, and food chains in this cool ecology science fair project.

In this science fair project, learn how a mineral streak is made and how it can help identify an unknown mineral.

Does the temperature of a magnet affect its strength? Learn about the relationship between magnets and temperature with this cool physics science fair project.

This science fair project on testing water hardness is a great introduction to practical chemistry. Test and learn the difference between hard and soft water.

In this simple science project, learn about what causes dew and what affects dew formation with a drinking glass, ice, and a soda bottle.

Learn about magnifying glasses, concave lenses and inverted images by sending rays of light through a magnifying glass in this cool science fair project!

This is a fantastic and easy science experiment where kids will learn about elasticity by testing how high bouncy balls of different materials can bounce.

Learn how to make a ping pong ball anemometerâa device used to measure wind speedâin this free science fair project idea.

Kids will conduct a cool limewater carbon dioxide test that can be performed with common household materials to learn about the chemistry of this common gas.

A homemade lava lamp gives any room a retro flair. Find out how to make a homemade lava lamp, and learn some science too, with this educational activity.

In this science fair project, you'll make a "ghost" appear in a test tube, and learn about what happens when hot water and cold water interact.

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.

What are buttress roots? In this fun science project, make a model of a rainforest tree and learn how they help trees survive in the tropical rainforest!

Kids will learn about the interaction of lactose and lactase in milk and discover why we describe enzymes as catalysts in this fun science fair project.

Kids build a desert food chain, desert food web, and desert food pyramid in this cool science fair project to learn about trophic levels and consumers.

In this fun science fair project idea learn about universal solvents and solutes and find out the solubility of several common liquid substances.

It's not actually that hard to get energy from garbage! Kids learn how to make biogas in the form of methane with this cool and easy science fair project idea.

Kids will learn how to make a steam powered rocket boat, also called a putt putt boat or a pop pop boat, in this great science fair project for 4th graders.

In this experiment, young ecologists will learn about a type of edge effect: how trees and plants at the edge of a forest can act as a weed filter.

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.

Kids learn how to prevent erosion by growing grass. They'll test soil with grass against raw soil in this revealing science fair project idea for 4th grade.

Check out this cool science project idea to learn about rocks and explore the cycles of formation, breakdown, and reformation of rocks in the Earth's crust.

This science fair project idea produces varying pitches of sound.

Introduce your fourth grader to the concepts of solstices by observing the length of her shadow on the shortest day of the year, compared to other solstices.

Discover whether different amounts of water added into a wine glass will produce a different pitch when their fingers are rubbed along the rim.