Check out this cool science fair project on identifying rocks and minerals for kids.

This two-ingredient dough, sometimes called "moon sand," is a quick and cheap way to let kids explore their senses, build fine motor skills, and play.

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.

In this project, you will observe and record changes in sunspots over two weeks.

Determine whether a hot liquid cools off faster when liquid is added before or after a two minute wait.

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

Is it solid or liquid? Create oobleck and witness the amazingly weird oscillation between the two!

Did you ever drink spoiled milk? Find out whether whole milk spoils at the same rate as 2% and skim milk.

Teach your little scientist about the amazing powers of gravity by comparing the falling speeds of two yummy fruits

This science fair project idea focuses on two classes of sugars monosaccharides (fructose) and disaccharides (sucrose or table sugar).

In this experiment, your child will create two compost bins and see if he can determine what attracts fruit flies.

Administer IQ tests to volunteers. have one group practice typical IQ test problems. Then compare results of the two groups.

This science fair project idea determines an average personâs ability to use their anaerobic power system over a period of 2 weeks.

Boost your preschooler's attention to detail by getting her to explore the differences between two different pumpkins: large and small.

Milk is made of water and fat; but how can you separate the two? Find out in this color changing milk experiment.

Monitor the impact learning how to play chess has an academic performance. Divide subjects into two groups compare GPA

Your preschooler can learn how to siphon water with just two bottles and a plastic tube in this fun, educational science activity.

This science fair project compares the allelopathic affects of juglone, a chemical agent produced by the Black Walnut tree, on two plants.

This science fair project investigates which of two learning modes most commonly used in school, visual and auditory, is better for information retention.

In this science fair project, high school students will try to determine the mathematical patterns in JS Bach's two movement preludes and fugues.

This science fair project determines which of two chemical agents can be used to release the drug (tea) from hydrogel crystals.

Determine whether cats have dominant paws. Observe which paw cat uses to reach for treats, feather, and string. Calculate percentage for two paws.

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

Science fair project that compares the biodiversity of fungi in different ecosystems by identifying species of fungi.

In this experiment two environments will be compared: a room with interior design that uses correct Feng Shui versus one with incorrect Feng Shui.

Show your fifth grade scientist how to create a siphon using two buckets, plastic tubing, and water. Watch her astonishment as the water travels uphill!

This science fair project idea teaches about the size of two different systems: the solar system and an atomic system.

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 fun science fair project, make two different scale models of our solar system using Astronomical Units and planets' relative size!