Easy STEM Activities for Kids: Experiments, Building Projects, and Printables

STEM activities give kids a chance to ask questions, build things, test ideas, and discover what happens. You do not need an expensive kit to get started. Many of these projects use supplies you already have at home or in the classroom.

This collection includes quick science experiments, LEGO building challenges, nature projects, and free science and math printables. Whether you need a 10-minute after-school activity or a longer project for family STEM night, you can find an idea that fits your day.

What Is a STEM Activity?

STEM stands for science, technology, engineering, and mathematics. A STEM activity helps children explore one or more of those subjects through observation, problem-solving, or hands-on practice.

A child building a LEGO parachute is exploring engineering. When they drop it, observe how it falls, and change the design, they are also using science and math. The activity does not have to be complicated. The questions children ask along the way are part of the learning.

Quick STEM Activities for Kids

Short on time? Start with one of these easy STEM projects. Preparation and cleanup times will vary.

About 10 Minutes

• Make a simple pinwheel and test where it spins best.
• Pick a building idea from our LEGO activities for kids. Challenge children to make the tallest tower they can with a limited number of bricks.
• Use a page from the scientific method worksheets to predict the experiment’s outcome or record an observation afterward.

About 30 Minutes

• Make an apple volcano or lemon volcano.
• Build and test a LEGO parachute.
• Create a DIY kaleidoscope and look for changing patterns.
• Build a Play-Doh volcano and use it for an eruption experiment.

A plastic bottle greenhouse can also fit into one project session, but the learning continues as kids check the seeds over the following days.

Easy Science Experiments for Kids

These hands-on STEM activities let children observe something fizz, grow, stretch, or change. Before you begin, ask, “What do you think will happen?”

Apple Volcano

Turn an apple into a small volcano with the apple volcano experiment. Kids can observe the reaction between baking soda and vinegar, then compare what happens when they change the amount of one ingredient.

Lemon Volcano

The lemon volcano STEM experiment makes a fizzy reaction inside a lemon. Try the activity with another citrus fruit and ask kids what stayed the same and what changed.

Pop Rocks and Soda

The Pop Rocks and soda experiment lets kids watch bubbles form and describe what they see.

Mentos and Soda Geyser

Take the Mentos explosion experiment outside to a clear, open space. Follow the project directions and have children observe the geyser from a safe distance.

Homemade Floam

Make homemade floam and explore its texture. Ask kids whether it stretches, bounces, or holds its shape, and let them describe how it feels.

For older students, pair an experiment with these free scientific method worksheets so they can record a question, prediction, observations, and conclusion.

Building and Engineering STEM Activities

Building activities give kids a problem to solve. They can make a first design, test it, and decide what to improve.

Build a LEGO Parachute

In this LEGO parachute activity, kids make a parachute for a small LEGO figure. Try dropping different designs from the same height and compare how they fall.

Make a Pinwheel

Follow the simple pinwheel tutorial, then test the finished pinwheel in different spots. Where does it spin fastest? What happens when there is no breeze?

Create a Kaleidoscope

A DIY kaleidoscope is a creative way to investigate reflections and patterns. Encourage kids to describe what changes when they turn it.

Build With LEGO Bricks

Try the LEGO lighthouse project, or browse our LEGO building ideas and printables for more inspiration. After children finish a model, invite them to add one feature of their own.

For a quick classroom or family challenge, place two books a short distance apart and ask kids to build a bridge between them. Test each bridge with a small toy, then give them time to redesign it.

Plant and Nature STEM Activities

Nature projects encourage kids to observe changes over time. They work especially well for homeschool lessons, classroom science centers, and curious children who like to check on a project every day.

• Plastic bottle greenhouse for kids: Build a small greenhouse and watch for condensation and seed growth.
• DIY lemon seed starter kit: Plant lemon seeds and track when they sprout.
• Pumpkin life cycle printable activity book: Explore the stages of pumpkin growth.
• Butterfly life cycle cut-and-paste worksheet: Put the stages of a butterfly’s life cycle in order.
• Sea turtle life cycle printable: Learn about sea turtles through sequencing, reading, and writing.

You can find more topics in our collection of life cycle worksheets for kids.

Free Science and Math Printables

Printables can help children label what they have learned, build a model, or record experiment results.

• Printable science worksheets for kids: Browse science activities for different lessons and interests.
• Scientific method worksheets: Guide students as they make predictions and record observations.
• Build a plant cell cut-and-paste worksheet: Assemble and label the parts of a plant cell.
• Build an animal cell cut-and-paste worksheets: Make a visual model of an animal cell.
• Solar system diorama printable: Build a model while learning about the Sun and planets.
• Math printables: Find number and math activities to support the M in STEM.
• Grocery store math game worksheets: Practice math with a familiar shopping activity.

STEM Activities for Preschool, Elementary, and Older Students

Preschool and kindergarten: Choose activities with visible results and simple questions. A pinwheel, apple volcano, or butterfly life cycle worksheet works well with adult help.

Early elementary: Invite kids to build and compare results. Try the LEGO parachute, plastic bottle greenhouse, or lemon volcano.

Older elementary and beyond: Ask students to explain their thinking and record evidence. Use the scientific method worksheets or explore biology with the plant cell and animal cell activities.

STEM Activities at Home, After School, and in the Classroom

At home: Start with supplies you already have. An apple volcano, a pinwheel, or a LEGO building challenge can turn an ordinary afternoon into a chance to investigate something new.

After school: Choose an activity that is easy to set up and finish. A short building challenge lets kids create and test something without needing a full lesson.

In the classroom or homeschool: Match a project to your current topic. Build a plastic bottle greenhouse during a plant unit, or use the scientific method worksheets alongside an experiment.

For family STEM night: Have each person build a LEGO parachute using a different design. Drop them from the same height, compare the results, and let everyone improve their parachute before a second test.

How to Make Any STEM Project More Meaningful

You can turn a simple activity into a deeper learning experience with three questions:

1. What do you think will happen? Let your child make a prediction.
2. What could we change? Choose one part of the design or experiment to test.
3. What did you notice? Talk about the result and decide what to try next.

A project does not have to work on the first attempt. When kids adjust a design and test it again, they get to practice the same kind of problem-solving that makes STEM activities so engaging.

Choose one project from this list and give it a try. If your children want to keep exploring afterward, browse these movies about science for kids and teens and talk about which ideas they would like to investigate themselves.