STEM for preschoolers: simple experiments - post

What does “STEM” mean for #preschoolers?

For preschoolers, STEM is not worksheets or long lessons. It’s learning through #play and curiosity. A “STEM moment” happens when a child:

• asks a question (“Why did it sink?”)
• makes a guess (“I think it will roll faster!”) 
• tries something (tests the idea)
• talks about what happened (shares results)

That’s real #STEM learning—just in a preschool-sized way. 

What makes a preschool STEM experiment “just right”? 

A good experiment for ages 3–5 should be:

• Safe (no small choking hazards, no strong chemicals)
• Short (5–15 minutes is plenty)
• Simple (few materials, easy steps)
• Repeatable (kids can try again and change one thing)

Also: it’s okay if it gets messy! Mess often means learning. #preschool #science

How do you keep STEM activities #safe (and still fun)?

Before you start, set a few clear rules:

• “Materials stay on the table.”
• “We don’t taste experiment items.”
• “Grown-ups pour anything that could splash.”
• “We wash hands when we’re done.”

If you want a quick refresher on staying present and preventing accidents during hands-on activities, this ChildCareEd article is a helpful read: Active Supervision: The Only Way to Care for Children

Which simple STEM experiments work best for preschoolers?

Below are easy, low-prep experiments you can do with common #classroom (or #home) materials.

1) What happens when we mix colors with water?

Materials: clear cups, water, food coloring, droppers/spoons, paper towels
Steps:

• Fill 3 cups with water (one for each primary color).
• Add a few drops of color.
• Let children transfer water to empty cups and “make new colors.”
• Try a “walking water” version: place paper towels between cups to watch color travel.

What kids learn: cause-and-effect, observing changes, #early #math (“how many drops?”)

2) Will it sink or float?

Materials: tub of water, small objects (spoon, cork, plastic toy, rock, leaf)
Steps:

• Show one object at a time.
• Ask: “Sink or float?”
• Drop it in and watch.
• Sort objects into two groups.

What kids learn: predicting, testing, sorting (a key math skill)

3) Can we build a ramp that goes faster?

Materials: cardboard, blocks/ #books, toy cars/balls, masking tape
Steps:

• Make a ramp (cardboard on books).
• Roll a car down.
• Ask: “What if we make it higher?” “What if we change the ramp surface?”
• Test changes one at a time.

What kids learn: engineering thinking, comparing, problem-solving

4) How can we make a bubble last longer?

Materials: dish soap, water, a little sugar or corn syrup (adult handles), straws/wands
Steps:

To extend this activity into a simple sustainability conversation, choose reusable bubble wands instead of disposable straws and discuss reducing plastic waste; National Skip the Straw Day offers a timely way to explore the topic.

• Mix a bubble solution (adult mixes).
• Blow bubbles and observe.
• Try bubbles on different surfaces (table, tray, paper towel).
• Ask: “Where do bubbles pop fastest?”

What kids learn: careful observation, experimenting with conditions

5) How many water drops fit in a circle?

This one is great because it’s both science + math in one activity.

Use this #free printable from ChildCareEd: Water Drop STEM Activity Buy Now $0.00

Materials: the printable, sheet protector, eyedropper, cup of water
Steps:

• Put the sheet in a protector (so you can reuse it).
• Children guess how many drops will fill each circle.
• They count drops and compare results.

What kids learn: counting, predicting, fine-motor control, early “data” thinking (#activity)

6) Can we grow salt crystals?

Materials: warm water (adult), salt, cup, string, pencil
Steps:

• Adults dissolve lots of salt in warm water (stir until it won’t dissolve easily).
• Tie a string to a pencil and hang it into the cup (not touching the bottom).
• Wait 1–3 days and observe.

What kids learn: patience, noticing changes over time, “solid vs. liquid” ideas

What should you say during STEM (so kids think more)?

Try simple question-starters: 

• “What do you notice?”
• “What do you think will happen next?”
• “What could we try differently?”
• “Why do you think that happened?”

Tip: Preschoolers don’t need the “right answer.” They need practice thinking and explaining.

How can you extend STEM learning with books and play?

After an experiment, keep the learning going with:

• A drawing journal: “Draw what you saw.”
• A building challenge: “Make a bridge for a toy.”
• A story connection: read a book about water, #weather, or animals and repeat the experiment with a new theme.

Which ChildCareEd trainings can help you plan better STEM activities?

If you want more ideas (and more confidence), these ChildCareEd courses connect well with preschool STEM:

• Building Early Science Foundations Buy Now $16.00:  Buy Now $16.00
• Math Foundations in Early Childhood: 
• Enhancing STEM Education for Infants and Toddlers Buy Now $16.00:  Buy Now $16.00

Even if you teach preschool, these trainings can give you practical ways to support curiosity, exploration, and early problem-solving.

Where can you get more ideas and follow ChildCareEd?

Want more activity ideas you can save and share with your team? Follow ChildCareEd on social and grab updates here: https://linktr.ee/childcareed