Use reusable, recyclable materials--along with a dose of imagination--to build a castle with first grade geometrical forms.

In this activity, young learners will make a balance using a plastic hanger and weigh a variety of small objects using candy corn.

Using an empty tennis ball can and a swimming pool, you will determine if it's possible to have a conversation under water.

Learn to solve a crime scene investigation using an important forensics tool: oblique lighting.

In this physics project, learn about the relationship between light intensity and distance using a laser pointer, flashlight, and graph paper!

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

Help your second grade scientist explore the timely topic of wind speed using a version of the classic Beaufort Scale.

Teach your first grade scientist the difference between liquids and solids using maple syrup.

Your child will do a fun science experiment using soap and pepper flakes to help understand the concepts of water molecules and the surface tension of water.

Here's a fun math and science activity: help your child explore four different kinds of measurement, using their hand and a few simple household tools.

Think you can blow up a balloon without using your mouth? This isn't just a cool trick, it's also a great way to introduce chemistry and biology concepts.

Make your own helicopter using a paper clip and a sheet of paper. Hold the spinner up in the air, let it go, and watch it spin gracefully to the ground.

This classic children's game demonstrates how sound travels through air vs. through a solid.

Play this flashlight game with your child to teach him about objects that are transparent, translucent, and opaque.

In this science fair project, young children discover what happens when two fluids that have different densities get together.

Blanket forts are a kid classic! Let your child create a âfortress of solitudeâ on his own for reading, telling scary stories or for cozy cocooning.

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

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.

How does the size of a vibrating surface affect the pitch of a drum? Learn about drum size and pitch with this easy science fair project idea.

Inspire your child to put on her engineer hat for the day, as she builds her very own, double-decker bridge.

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.

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.

What's cooler than an explosion? Not much! This simple science experiment lets kids build their own pop rocket. So put on your safety goggles and let her rip.

Make a DIY golf putter and design your own golf putting course in this 2nd-3rd grade arts and crafts/game activity.

Magic, science, or household cleanser? Let your second grader decide with this practical, nontoxic chemistry experiment with acids and bases.

Science fair project that examines what causes thunder and why a thunderclap sounds so loud. How is lightening related to the creation of sound waves?

Hone your child's skills of observation and take a look at forensic science for an interesting afternoon of exploration and detective work!

Try the classic balloon-on-the-wall trick with your kid and watch static electricity in action.

Chemistry is a blast with this backyard bomb made from a sandwich bag. All you need are ingredients from the pantry to create a satisfying, and safe, explosion.

In this Halloween-themed activity, young learners will find out what happens when they mix two household items together to create a surprising chemical reaction.