25 STEM Activities Easy Enough for Preschoolers

Use recyclables and household objects to build a better bridge.
Use recyclables and household objects to build a better bridge.
5/16/23 - By Ally Noel

STEM activities are all the rage in education right now, and for good reason. Science, Technology, Engineering, and Math (STEM) – and the Arts for STEAM – are crucial to kids’ learning and our future. But how to get your younger children interested? They might not be ready for coding, but many preschoolers under age 5 can enjoy some basic STEM principles through play.

Below we've got easy instructions to help you and your budding scientist build an apple boat or a toothpick-marshmallow castle, attempt a pom-pom drop, or indulged in baking soda science. Read on for a list of 25 tried-and-true screen-free STEM activities to do with your preschooler.

For more science experiments for kids of all ages, check out our list of 64 easy science experiments for kids, try our colorful Skittles science experiment, or enjoy one of our magical light experiments for toddlers and preschoolers—all of which can be found in our Guide to Science Experiments for Kids. Happy discovering!


Before you get started, any good scientist gathers the tools and ingredients they will need. My daughter and I assembled a “tinker box,” and it was refreshing to see how many things we had on hand. Into our tinker box we gathered: popsicle sticks, masking tape, red plastic cups, food coloring, mason jars, cotton balls, plastic utensils, coffee filters, loose change, and toothpicks. Then we were ready to start building, sorting, and experimenting—any time I determined we needed a break from screens!

1. Build an Apple Boat

James may have tried to set sail in a peach, but an apple would have built a sturdier vessel. Learn how to build an apple boat and set sail for the open seas (or nearest bathtub).  

2. Check Out Your Library

Libraries are a great place to discover STEM. Many host all kinds of FREE classes, events, and workshops to introduce their youngest patrons to STEM.

3. Engineer with Marshmallow Shapes

Develop engineering skills while constructing basic shapes out of toothpicks and marshmallows. You can build shapes using the marshmallow as a connector to hold the toothpicks together. Challenge your kid to invent new shapes or build three dimensionally. Make a castle, or a car! Get creative.

RELATED: 25 More Preschool Science Experiments

Coffee-filter chromatography is a fun way to combine art and science. 

4. Experiment with Coffee-Filter Chromatography

This laboratory technique separates pigments to see how many colors it takes to create a marker. With a magic marker draw a thick circle around the center of the coffee filter where the ridged part meets the center. Fold the coffee filter in half and then in half again to create a cone shape. Using a shallow glass of water, set the tip of the filter cone into the water. Be careful not to get the marker ring wet. Watch and observe the colors flow up the paper. Talk about molecules and the uses of chromatography in the lab.

5. Make Magic, aka an Ice Melt

Demonstrate “change of state” by melting ice with salt. Fill a bowl with water, and let it freeze overnight. Add a few drops of liquid water color if you want to color your ice. Remove the ice from the bowl and place on a tray. Simply shake table salt over the ice and watch the magic happen. Talk about the properties of each item that caused this change of state.

6. Sprout Seeds in a Jar

Pour about a teaspoon of Chia seeds into a mason jar and cover with about one cup of water. Using an elastic band, secure a piece of cheese cloth on top and allow to sit over night. In the morning, drain the water. You should see sprouting in a day or two!

7. Test Building (and Reading) Skills with a Solo Cup Tower

Add some literature to your STEM by building this Cat in the Hat tower with solo cups and pieces of paper. A basic understanding of physics is required for success!

RELATED: Easy Science Experiments to Do with Kids at Home

Make a baking soda mosaic with just a few ingredients.

8.  Play with Baking Soda Science

A little baking soda and vinegar can open a whole world of fun to tiny scientists. Cover the bottom of a foil tray with baking soda. Fill an ice cube tray with vinegar––for extra fun you can add a drop of food coloring to each compartment. Using a dropper or pipette (great for fine motor skills, too!), watch the baking soda fizz and froth in a chemical reaction.

Once they've mastered this simple version, it's time to up the wow factor, and make a glitter volcano with baking soda!

9. Dissect a Flower

Kids are naturally curious about their natural surroundings. This flower dissection lets them dive right in to the natural world around them, including a little botany, or plant science.

10. Create a Rain Cloud in a Jar

This is one storm I can handle! This fun and easy experiment demonstrates how rain forms in clouds, a natural project for little kids who are always curious the sky and everything that falls from it.

11. Plant a Garden

Gardens grow more than just fruits and vegetables; they can plant the seeds for early STEM education. From planning a garden that will attract birds and bees to counting seeds, this project hits all the marks. You might even find yourself talking nitrogen, precipitation, and more advanced subjects.

12. Go on a STEM Hike

Take this show outside, get some fresh air, go for a hike, learn something, AND get some weeding done- then a STEM hike is for you.

RELATED: 12 Recycled Crafts for Kids to Celebrate Earth Day

Build a bridge and test its strength.

13. Build a Better Bridge

Use recyclables and household objects to see who among you can build the strongest bridge. How many toys can each bridge hold before collapsing?

14. Make Pyramids with Egg Cartons

If you ever get the feeling that your kid would build the next Great Wall if only you had enough blocks, then egg carton building blocks are for you! Construct towers, pyramids, and more.

15. Build a Pom-Pom Drop

This STEM challenge an be assembled with paper rolls, tape, and a wall, and it looks super cool once constructed. Toddlers will delight in dropping the colored pom-poms through the tubes and watching them come out the other side.

16. Craft a Sugar Cube Masterpiece

Sugar cubes aren't just good for tea and coffee; kids can use them to construct an igloo, ice castle, tower, or anything they can imagine. Just mix a little water and confectioners sugar together until it forms a paste like “cement” to hold your sugar cubes together.

17. Host a Building Contest

Teamwork makes the dream work! When have you ever seen a construction site with ONE person? NEVER! Pool your resources (blocks, cardboard boxes, Manga-tiles, Duplos) and host a construction play date!

18. Paint With Rain

Check out these five different ways to paint with rain, and make some predictions about the outcomes. Check out more rainy day activities here.

19. Make Seed Bombs

Inch by inch, row by row, somebody make this garden grow! Seed bombs are a fun lesson in mixing proportions, plus kids get a cool finished product, which is always satisfying. Check out a cool recipe for making wildflower seed bombs.  

RELATED: 30 Days of Indoor Activities for Kids

Ready to make water walk to create a rainbow?

20. Turn Water into a Walking Rainbow 

A walking rainbow covers all your hands-on-STEM bases: squirting color, pouring water, making observations, and predicting outcomes. It also looks really pretty, drawing the eyes of little scientists. We had so much fun with this experiment, we not only wrote up exactly how to do it, but we made a video!

21. Make ’em Fly with a Marshmallow Catapult

There’s a lot of science behind making those marshmallows fly. Learn how to design a catapult.

22. Will it Float or Sink?

Fill a small tub with water. Gather objects from around your house or yard and place them in the tub, pool, or sink. Ask you son or daughter if the object sank or floated and see if you can figure out why. Increase the challenge to see if they can predict which will happen before you drop it in.

23. Grow Food from Trash

Instead of tossing out the base of a celery stalk, regrow it into new plants. Place the celery in a small saucer or bowl with water, base side down. Let the celery sit in the water for about a week. New celery will begin growing from the center of the base. After you have a bit of new growth, transfer the plant into a pot with soil.

24. Make a Polymer

Combine glue, water, contact lens solution, and baking soda to create a polymer––more commonly knows as slime

25. Create Your Own DIY Tinker Kit

Although there are plenty of fancy, STEM subscription boxes for kids these days, you can actually make your own––just as we did––for very little money. Bring it out on any rainy day, or to create an impromptu screen-free moment with your kids. Check out this DIY one using mostly Dollar Store items.

All photos by the author