Would it hurt to skip brushing your teeth just this once? Let's find out by seeing which foods produce the most mouth bacteria.

Study the life cycle of the common blowfly as it relates to forensic investigation. Record the first time you see flies, maggots, and eggs.

These flying potato poppers make a cool sound, create a celebratory mood, and they can teach your child about the power of air pressure.

Can you increase the light and plant growth in your garden using mirrors? In this experiment, measure light reflection and find out!

How does distance affect the spreading of light? Kids see diffraction and the inverse square law of light in action with this great science fair project idea.

Science fair project that examines how winter storms form and the relationship between temperature, moisture and snow.

The goal of this evaporation experiment is to learn about how different external conditions affect drying time.

This science fair project focuses on a polymer called hydrogel super absorbent crystal which absorbs water, swelling to many times its original size.

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

Learn whether Mylar Balloons last longer than Latex Balloons or vice versa.

This science fair project idea determines which method of hand cleansing is the most effective.

Check out this fun and easy 4th grade science fair project idea that tests how gravity induces positive and negative geotropism (gravitropism) in bean plants.

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

Let your fabulous crafter use their favorite flowers, fruits and herbs to whip up a delicious perfume that they can proudly present to a friend or a loved one.

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.

In this science fair project, students create their own miniature salt flats at home.

In this science fair projects, students will grow out the bacteria that collect on air conditioner filters.

The objective of this science fair project is to observe the differences in heat absorption for darker colors vs. lighter colors.

This experiment explores whether reading text on a computer screen or type on paper leads to better retention of the information read.

Science fair project that examines condensation and the conditions needed in order for dew to form.

This science fair project idea explores the different properties of matter.

This science fair project idea investigates the ability of different whitening toothpastes to whiten teeth.

To help your child learn how to use a thermometer, try this temperature collecting activity at home.

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

Make water and clay play a little more scientific with this hands-on experiment that teaches displacement and shows how an object's shape affects its buoyancy.

Challenge your learner to design and build a city of their own in this creative engineering activity.

Science fair project that examines how to grow bacteria in a controlled setting, using simple materials from around the home.

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.

This science fair project idea measures out the sugar of various foods and find out whether people can correctly determine how much sugar is in common foods.

Science fair project that examines albedo, and how this information is applied in the design of cars, sportswear, and other items. Which colors reflect light?