Learn about this simple machine and make a pulley of your own to use for fun science trials.

Make a backbone model to explore human anatomy and life science.

In this science fair project, learn how to make gears and find out why they transmit torques in predictable ways.

Learn how to make a hygrometer to measure relative humidity in this project. Make a sling psychrometer hygrometer with gauze, thermometers, and a bottle.

Learn how to make an anemometer with step-by-step instructions in this cool science fair project idea for 4th grade.

Show your preschooler how to make a print of a butterfly using her hand as a tool--a great way to stimulate her sense of touch.

Make scented sensory cloud dough. Add it to a sensory table, activity station, or put it in a baggie for extra at-the-park entertainment!

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

Learn how to make a periscope with this cool engineering science fair project idea, and learn about optics to learn how a periscope works.

Create safe lightning for kids! They'll learn how to make lightning at home with this fun science fair project idea illustrating static charges and grounding.

Help kids tap into their inner inventor by teaching them how to make peanut butter through trial, error, and lots of taste testing!

Kids will learn how to make a thermometer to to explore liquid density in this great science fair project. Which liquids are affected by temperature the most?

Make homemade lemonade in a baggie with your preschooler with this fun and easy recipe.

Check out this cool and free middle school science fair project idea on how to make a solar oven.

This basketball project explores the best way to make the perfect shot every time.

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

Discover whether eating certain foods will make you smell (not only bad breath) but through skin cells.

Make an edible play dough with your child to help her develop her sensory and motor skills.

In this hands-on design challenge your child will make their very own Rube Goldberg Machine.

Slime: It's oozy, it's goopy, and it's just plain fun! Learn how to make slime with this fun science fair project.

In this cool science fair project, kids apply basic algebra to learn how to make a PVC pipe instrument while exploring concepts like frequency and resonance.

Kids get step-by-step instructions for how to make a rubber band car and explore the physics of potential energy with this fun engineering science fair project.

Kids learn how to make a simple electric motor in this great engineering science fair project that teaches them how current generates its own magnetic field.

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.

Kids will love making clouds and learning how to make a water cycle model in this fun science fair project idea that explores evaporation and precipitation.

Science fair project that demonstrates how a rainbow forms, by using water to split white light into its many colors.

This is a fun and inexpensive project and it's a great way for your child to build basic geometry skills, like shape recognition and pattern/angle familiarity.

Test whether cutting up meats will make it cook faster than just cooking it whole.

Your preschooler will engage their senses by making a scented pumpkin to decorate your house.