Science Buddies' third grade science projects are the perfect way for third grade students to have fun exploring science, technology, engineering, and math (STEM). Our third grade projects are written and tested by scientists and are specifically created for use by students in the third grade. Students can choose to follow the science experiment as written or put their own spin on the project.

For a personalized list of science projects, third graders can use the Science Buddies Topic Selection Wizard. The wizard asks students to respond to a series of simple statements and then uses their answers to recommend age-appropriate projects that fit their interests.

Select a resource
Filter by
Sort by
Science Fair Project Idea
Check out this video from former NASA engineer Mark Rober, where he sets out to reclaim his title for the world's largest and tallest elephant toothpaste reaction. In the video, he experiments with different container shapes and sizes to determine which will result in the most spectacular reaction. You can turn this into a science project of your own! How do differently sized or shaped containers affect the foaming reaction? Can you find an optimal container that makes the reaction go the… Read more
Science Fair Project Idea
Do you think you could build a car powered by nothing but air? A balloon-powered car is pushed forward by air escaping from a balloon, and it is fun and easy to build with materials you already have around your house. Can you imagine how you would want your own balloon-powered car to look? Can you design a car that will travel as far as possible? You can even measure your car's speed using your smartphone and Google's Science Journal app. Get ready to grab some simple supplies to bring your… Read more
Science Fair Project Idea
Just one sheet of paper can lead to a whole lot of fun. How? Paper planes! All you have to know is how to fold and you can have a simple plane in a matter of minutes! But what design should you use to build the best plane? In this aerodynamics science project, you will change the basic design of a paper plane and see how this affects its flight. Specifically, you will increase how much drag the plane experiences and see if this changes how far the paper plane flies. There is a lot of cool… Read more
Science Fair Project Idea
Does green apple juice taste the same as red apple juice? That might seem like a silly question. Food coloring does not have any flavor—so how could it change how something tastes? Find out whether it does in this food science project! Read more
Science Fair Project Idea
To be able to live on Mars, humans need breathable air, clean water, and nutritious food. Spacesuits can provide oxygen to breathe, ice on Mars can be a source of water, but how could we get nutritious food? Today's astronauts bring food with them. But a manned trip to Mars would require food that was either successfully grown in space or on Mars, as taking the extra weight of food for such a long time—it takes 6–9 months one way—is just too costly. In this project, you will… Read more
Science Fair Project Idea
Have you ever suffered from poor Wi-Fi reception for your smartphone, tablet, or laptop? Certain materials can actually block a Wi-Fi signal; do you think that could be part of your problem? In this science project, you will do an experiment to find out which materials cause the biggest drop in signal strength from a wireless router. Read more
Science Fair Project Idea
Where do you get your best ideas? At school with your friends? When you are out for a bike ride? Over 2,200 years ago, a scientist named Archimedes got one of his best ideas when he sat down in his bath. Eureka! He went running through the streets without even bothering with his clothes. What was he so excited about? He had discovered that when objects, like his body, are placed in water, water is pushed out of the way. Have you noticed that, too? The weight of the water that is pushed out of… Read more
Science Fair Project Idea
Have you ever wondered why apple slices turn brown once you cut them, or why a yellow banana gets dark spots over time? In this project you will find out why this happens, and how you can keep your apple slices looking fresh! Read more
Science Fair Project Idea
Try your hand at this engineering challenge. Can you build a "launcher" device to launch a ball as far as possible and a "receiver" to catch it? Building a receiver provides an extra twist to a traditional catapult project. Add to the challenge by using a limited set of materials to build your machine and calculate a score based on your throw distance and materials used. Read more
Science Fair Project Idea
"Plastic made from milk" —that certainly sounds like something made-up. If you agree, you may be surprised to learn that in the early 20th century, milk was used to make many different plastic ornaments —including jewelry for Queen Mary of England! In this chemistry science project, you can figure out the best recipe to make your own milk plastic (usually called casein plastic) and use it to make beads, ornaments, or other items. Read more
1 2 3 4 5 ... 34 >
Free science fair projects.