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Last Minute Science Fair Projects for Kids

Last Minute Science Fair Projects for Kids

Raise your hand if you’re a procrastinator. The struggle is real and it seems to worsen when my children have a project due. Science fair projects seem to be the hardest ones to get started. I swear they sneak up on you the most. You feel like you have weeks. Then all of a sudden, your child is reminding you the project is due on Friday. Where did all the weeks you could have started the project go? So, if you are looking for some last minute science fair ideas, you’ve come to the right place. 

Scientific Method

Before starting any fun experiment, you want your child to look at the scientific method. There are 7 parts of the scientific method. You want your child’s simple science experiment to include the steps of the scientific method. It’s essential to focus on the process of science, not just the experiment. Be sure to discuss how to get the best results. Scientists follow very simple steps.   

  1. Ask a question
  2. Perform research
  3. Establish your hypothesis
  4. Test your hypothesis by conducting an experiment
  5. Make an observation
  6. Analyze the results and draw a conclusion
  7. Present the findings



You can download and print this FREE scientific method worksheet to guide you through the process. 



18 Last Minute Science Fair Ideas

If you are looking for some super-quick ideas, these fair ideas will please any science teacher. These easy science experiments can be completed in a week or less and will let you keep moving on with your daily lives without having to sit at home creating an elaborate fair experiment. 

Static Electricity

This simple experiment involves different types of balloons and your hair. Grab a couple of different kinds of balloons. Some examples of different types are the pearl finish or matte finish. You can try latex balloons or mylar balloons. Rub the balloons on your head and measure how high your hair stands. Does the type of finish or ball affect how tall your hair stands? Or how long it stands? 

Exploding Sandwich Bags

Does your child love chemical reactions? This cool science experiment might be the simple experiment you’ve been looking for. See how mixing baking soda and vinegar will react when trapped inside a zipped plastic bag! 

Plant Growth

Now, you might think plants need a lot of time to grow. However, wheat seeds grow quickly (within a day or two) and can make for a simple experiment. Fill up a couple of cups with soil, and plant some wheat seeds. Give each cup a good amount of water. Place one cup on a sunny windowsill and the other in a black plastic bag. What will happen to the plants? Will the one in the bag still grow? If you want to find out which seeds grow faster, try an experiment with different types of fastest growing seeds.

Solar Oven 

The perfect energy transfer experiment.  Create an oven that uses the sun to cook items. Aluminum foil and plastic wrap will do most of the hard work. Have your child make a list of foods that could be cooked in the oven. Some good foods are s’mores, pizza, or a quesadilla. 

Ice Fishing

This experiment uses an ice cube (or more), a piece of string, and salt. Place ice cubes in a bowl of water. They should bob on top. Place a piece of string on the ice cube(s) and shake a little salt on top. Within a few seconds, you’ll be able to pull the string up, and all the ice cubs will be attached! 

Glowing Jello

Jello is the type of food every little kid loves. But did you know that you can make jello glow? Yes, you can create a glow-in-the-dark treat. Using tonic water instead of a regular cup of water will make jello glow when exposed to a black light. Pretty cool, huh? 

Stomp Rockets

These juice rocket launchers are super fun. Have your child experiment with different types of juice pouches. All you need are some empty juice pouches, a pencil, paper, and scissors! Do the Kool-aid pouches launch further than the Capri-sun? Does the design of the paper rocket change how far it can fly?  Use a measuring tape to measure precisely how far each rocket flies.

Moldy Bread

Bacteria growth makes for a pretty cool science experiment. Grab a couple of pieces of bread. Touch one with dirty hands and one with clean hands. Put them into sandwich bags and see which one grows mold first. The mold should start to grow pretty quickly.

Sound Waves

Learn all about sound waves and how they travel and sound different underwater using this simple science experiment. All you need are a couple of forks, spoons, or other utensils, and some water. Listen to how the sound changes when they are rattled together out of the water and under the water. Maybe try with different liquids like juice or soda. I wouldn’t suggest jumping into a bathtub of either of those though.

Ames Chair

Ames chair is a famous optical illusion where a few lines can create a chair! It does involve quite a bit of material, but many of them you’ll probably already have at home or can be found at your closest big box store like Target or Walmart. 

Taste Buds Test

If you didn’t know, there are different positions of tastes on your tongue. Different parts of our tongue taste different things, like sweet, sour, and bitter. Using household cooking ingredients like lemon juice and sugar, you can test that out. 

Magic Milk Experiment 

Learn all about surface tension with this magic milk experiment. Gather up different colors of food coloring and watch what happens when you touch each colored spot with dish soap! See if other brands of dish soap cause the food coloring to act differently. What causes the food coloring to move?  It is a great science experiment and pretty fast too! 

Balloon Rockets

This experiment is all about potential energy! Strings, straws, and balloons are all you need for this fun experiment. See which balloon goes fastest and gets to the finish line first. Try different-sized balloons and different length races to try different hypotheses. 

Lava Lamp

Making your own lava lamp is another cool experiment. Most of us had them when we were little, and now we can create one using different colors of food coloring and oil. Clear plastic bottles work best for lava lamps—a simple experiment and super easy with minimal prep or materials. 

Rubber Band Darts

Rubber bands have a ton of potential energy. Grab a bunch of different size rubber bands and see just how far you can sling them. Make sure you ask questions like: does the thickness of the rubber band make them go further or not? Does pulling them back 20 cm make them go further than 10 cm? 

Walking Water

Using paper towels, glasses, food coloring, and capillary action. Your child can make water “walk” to different glasses. Although capillary action is very slow moving, you will eventually be able to see what happens after an overnight soak. You can also show capillary actions with flowers. Grab some white flowers and put them in colored water. Eventually, those flowers will become the same color as the water. 

Warmth And Blubber

If you have an animal lover in your house, this blubber experiment may be the perfect easy project for their science fair. Grab a plastic bag, vegetable shortening, and cold water. Have your child place their hand in the bag of vegetable shortening and see if they feel the cold water. Have them use the other hand and stick it in the cold water without the shortening. What is the difference? Why is that? 

String Phone

Everyone has a cell phone now. That means the old string phone experiment will blow your child’s mind! Create a simple string phone and discuss with your child why and how it works. 



Great Ideas And Display Tips

Okay, now you have completed the best science fair project with only days to spare and still have to complete the display board. Display boards can make or break great ideas and make simple ideas shine bright. 

Here are some quick science fair display tips:

  • Simple is better, and it should be neat and organized.
  • Always have a powerful title. It should grab visitors’ and judges’ attention (if your science fair is competitive). 
  • Know your facts, and show your report, data, materials, and conclusions. It should all be well-written (and written by your child). 
  • Make it attractive and creative. Use pictures, objects, colors, graphs, charts, etc. 
  • Practice and review. Have your child practice and review what their project is all about. Don’t be afraid to ask them questions about their project, which will help them prepare. 

Last Minute Science Fair Ideas

These 18 last minute science fair ideas are just the tip of the iceberg. There are so many great ideas out there. But, whether you’re a procrastinator or your child just sprung the science fair project idea on you. These last minute science fair ideas will get you moving in the right direction, and hopefully, you’ll find the perfect idea for your child to complete.