15 Easy STEM Activities for Kids Using Things You Already Have
Pepper, a penny, a balloon, and a black marker are enough for the first few easy STEM activities on this list, and each one takes about half an hour, cleanup included.
For every activity, we’ve listed the time, what you’ll need, and the idea your child is actually learning, whether that’s surface tension, friction, or how a computer follows instructions. Most work for ages 5 to 11, and we’ve noted where younger or older kids need a twist.
The first 12 use only things from around the house. The last three take earlier activities further with a 3D printer, for families who have one or are curious about it.
What Makes a STEM Activity Easy, and Still Worth Doing?
We’d call an activity easy if setting it up takes less time than finding the scissors. It’s worth doing if your kid has to make a guess before anything happens, because that guess is the science part. Our guide to what STEM education means for kids explains why.
Predict, Test, Then Change One Thing
Most of the activities below run on the same loop, even if nobody calls it that. Your kid guesses, tries it, and then changes one small thing to see what happens. At a lot of kitchen tables, that sounds like “Wait, let me try it with the big car.”
Your Kitchen Already Has the Supplies
You don’t need a STEM kit for any of this, or one of our 3D printers made for curious families for the first twelve. If there’s pepper in the cupboard and a few pennies in the junk drawer, you can do most of these simple STEM activities tonight.
Easy Science Experiments With Household Items (Activities 1 to 5)
Start here if your kid is on the younger side. These five get the fastest reactions, and they’re all science experiments for kids at home that happen at the kitchen sink with almost no prep.
1. Make the Pepper Run Away (10 Minutes)
You’ll need a cereal bowl of water, a few shakes of black pepper, a drop of dish soap, and one cotton swab.
Shake on pepper until the water looks gray and fuzzy. When your kid pokes the middle with a dry swab, almost nothing moves. The second try, with a dab of dish soap on the tip, sends the pepper racing to the edges, and they’ll want to go again.
What’s going on is surface tension. Think of the water’s surface as a stretched sheet of rubber. Soap breaks it in the middle, and the rest of the sheet pulls back toward the edges, carrying the pepper along.
2. How Many Drops Fit on a Penny? (10 to 15 Minutes)
You’ll need a penny (any small coin works), a glass of water, an eyedropper or a straw, and a paper towel to catch the spills.
Ask for a guess before the first drop. A lot of kids say five. The water has other plans, bulging into a dome that can hold twenty drops or more before it spills, and by then everybody at the table is counting out loud.
The drops hold together because water molecules cling to each other, which is the same surface tension from the pepper bowl. Wisconsin 4-H uses this exact test in its surface tension activity plan. Stir a little soap into the glass, try again, and the count usually falls by a lot.
3. The Arrow That Flips in a Glass of Water (10 Minutes)
You’ll need a clear drinking glass, a jug of water, and an arrow drawn in thick marker on a scrap of paper.
Prop the paper a few inches behind the empty glass with the arrow pointing left, and let your kid do the pouring. Somewhere around halfway up, the arrow seems to swing around and point right. Sliding the paper back and forth changes the exact moment it flips.
That’s refraction. Light bends when it passes through water, and a round glass full of it acts like a magnifying lens that turns the picture around. The reversing arrows activity from the Glasgow Science Centre has a short video if you’d like to see it first.
4. Balloon Soda Can Race (10 to 15 Minutes)
You’ll need one balloon per racer, an empty soda can for each, and a stretch of smooth floor.
Most of the giggling happens before any science, while the balloon gets rubbed on somebody’s hair. Then hold it near the can without touching it, and the can starts rolling toward the balloon by itself. If you have a second can and a second balloon, race them down the hallway.
This one is static electricity. The NSTA explains it for teachers like this: rubbing piles extra electrons onto the balloon, which pushes the can’s own electrons to its far side, so the near side gets pulled along.
5. Find the Secret Colors in a Black Marker (20 to 30 Minutes)
You’ll need a few coffee filters cut into strips, two or three different black markers, a cup of water, a pencil, and some tape.
Each strip gets a dot of black marker an inch from the bottom. Tape the strips to a pencil laid across the cup so only their tips dip into the water. As the water climbs, the black splits into blues and purples, and each brand looks a little different.
That’s chromatography, which is how scientists separate mixtures. The National Inventors Hall of Fame marker mystery turns it into a detective game, where kids work out which marker “wrote” a mystery note.
Simple STEM Challenges to Build and Test (Activities 6 to 9)
If your kid is the type who builds a tower just to knock it down, this section is theirs. Each of these engineering and physics activities for kids ends with something being tested until it fails, and older kids can keep score.
6. Paper Columns That Hold Up Books (15 to 20 Minutes)
You’ll need three sheets of printer paper, tape, and a pile of paperbacks that nobody minds squashing.
We’d fold the first two sheets into a triangle tube and a square tube, roll the third into a plain round one, and tape each seam. Your kid then adds books one at a time until each column gives way. The round one nearly always wins by a mile.
A cylinder spreads the weight evenly around its walls, while the corners of the other shapes buckle first. The strongest column activity from Michigan 4-H runs the same test with six books.
7. Step Through an Index Card (15 Minutes)
You’ll need one index card or an old postcard, plus scissors.
Tell your child they can climb through one index card and watch them laugh. The secret is a long fold down the middle. After a row of cuts from alternating sides and a snip along the fold, the card opens into a loop wide enough to step through.
It’s a puzzle about perimeter, since the cuts stretch the card’s edge into one long loop. NRICH at the University of Cambridge has the folding steps with pictures, and kids 8 and up can try to beat their own loop with a thinner strip.
8. Toy Car Ramp Race (15 to 20 Minutes)
You’ll need two or three toy cars, a cutting board or a big hardcover to use as a ramp, books to prop it up, a bath towel, and a tape measure.
Let a car roll from the top and mark where it stops with a bit of tape. On the next run, drape the towel over the ramp. For the third race, take the towel away and slide one more book under the ramp instead.
Kids see gravity and friction working against each other. The trick we’d push is changing only one thing per race, which is exactly how real tests are run.
9. Rubber Band Guitar (20 to 30 Minutes)
You’ll need an empty tissue box, four or five rubber bands in different thicknesses, and two pencils.
Once the bands are stretched across the hole, a pencil slid under each end lifts them clear of the box so they can ring. Lining them up from lowest to highest note takes more listening than you’d think. Moving one pencil closer to the other makes every note jump.
It’s about vibration and pitch. Science Buddies’ rubber band guitar explains that tighter, thinner, and shorter strings all vibrate faster and sound higher, which is the same reason a real guitar has thick strings for the low notes.
Easy Math and Tech STEM Activities (Activities 10 to 12)
STEM isn’t only science. These three quick STEM activities cover estimating, shapes, and the way computers follow instructions, with no screen involved.
10. Estimation Jar (10 to 15 Minutes)
You’ll need a clear jar, like an old pasta sauce jar, and enough dry pasta, beans, or buttons to fill it.
Guesses go on sticky notes first, folded so nobody can peek. Your child then counts one small cupful and works out how many cupfuls fill the jar, which gives a smart estimate before everything gets tipped out for the real count. The closest guess picks dessert.
This builds estimation, which is a real math skill and a surprisingly hard one. Kids often miss by a mile on the first jar and get much closer by the third.
11. Fold and Cut a Paper Tangram (About 20 Minutes)
You’ll need a square of paper, which you can make by trimming a printer sheet, and scissors.
A few folds and six cuts turn one square into a whole tangram set, with five triangles, a small square, and one slanted parallelogram. Putting it back together is the part that keeps kids busy, sometimes for ten minutes or longer.
Along the way your kid notices things a worksheet would have to spell out, like two small triangles covering exactly the same space as the square. That’s geometry learned with their hands. Once the square is solved, try making a cat.
12. Program a Parent Like a Robot (15 to 20 Minutes)
You’ll need paper, a pencil, and a stack of six plastic or paper cups.
Your child draws arrows on paper to tell you how to stack the cups into a shape, and you follow only what’s written, no matter how silly it gets. When the stack goes wrong, they find the bad step and fix it.
That’s an algorithm and debugging, the two ideas at the heart of coding. It’s based on Code.org’s My Robotic Friends lesson, which classrooms use to teach programming with no computer at all.
Take Three Activities Further With a 3D Printer (Activities 13 to 15)
Paper and cardboard are great for trying ideas. A 3D printer helps when your child wants parts that come out the same every time, so a test can be repeated fairly. For a much longer list of projects, see our best 3D printing ideas for kids.
The times below are for the activity itself. Print the parts the day before, since even small prints take a while, and an adult should run the printer.
13. Print a Tangram Set That Lasts (20 to 30 Minutes)
You’ll need the paper tangram from Activity 11 and a printed set. Print the pieces ahead of time, since printing isn’t part of the 30 minutes.
Once the paper version gets floppy, a printed set that clicks into a little tray lasts for years.
On the X-MAKER JOY from AOSEED, a tangram set from a free model file can print while your child is at school. You load the filament and start it, and the pieces are waiting when they get home.
Then set the printed pieces next to the paper ones. Homemade cuts are almost always a little crooked, and spotting where yours went wrong is a sneaky lesson in measuring.
14. Ramp Cars With Wheels You Can Swap (20 to 30 Minutes)
You’ll need the ramp from Activity 8, a printed car body, and two printed sets of wheels, one small and one large, all printed the day before.
Your child races the same car down the same ramp, changing only the wheels. Printing each set in its own color from our AOSEED filament set with four colors makes the results easy to keep straight on a scoresheet.
Kids usually expect the big wheels to win. Sometimes they do and sometimes the small ones roll farther, and working out why leads straight into friction and weight.
15. Turn the Robot Game Into a Board Game (20 to 30 Minutes)
You’ll need printed arrow tiles, a small printed robot token, and a grid drawn on a big sheet of paper. The tiles should be printed ahead.
This moves Activity 12 from paper onto a game board. Kids lay out arrow tiles to steer the robot token to a goal square, then swap seats so someone else has to follow their program.
In the X-MAKER App’s design tools, they can sketch their own robot and add it as a token. Printed tiles also survive the dog, which paper ones don’t.
How to Keep Kids Interested Past the First Ten Minutes
Teachers on Reddit say a lot of STEM activities start strong and lose half the room after about ten minutes. A few habits stretch that out.
Start With a Guess
Asking “What do you think will happen?” before anything starts gives your child a stake in the result. Writing the guess down makes it even better.
Turn Results Into Numbers
Count the drops, measure the distance, and tally the books. A simple chart on the fridge makes the next round feel like a rematch, not a repeat. For ideas on what to make next, see what other families have made in our AOSEED Creative Hub project gallery.
Let Them Fix Their Own Mistakes
A crumpled column or a car that won’t roll is the best part of the lesson, as long as you resist fixing it for them. When they want more ideas, there are 40 in our guide to STEM activities for kids at home.
Keep Safety Simple
Balloons and tiny printed parts should stay well away from toddlers, since both can be swallowed. Younger kids will need you on scissor duty for the index card and the tangram, and the hot nozzle on a 3D printer is always an adult job.
Final Thoughts on Easy STEM Activities for Kids
Pick one activity for this weekend, ideally the pepper or the penny, since both take ten minutes and get a reaction. If your child asks to do it again with one thing changed, they’re already thinking like a scientist.
When you’re ready for more, you’ll find printers, kits, and project ideas at AOSEED, home of the X-MAKER JOY.
FAQs
What are some fun STEM projects for kids?
Anything with a winner tends to be the most fun, so we’d start with the soda can race or the paper column contest. We’d put the rubber band guitar right behind those two, since it’s the only one where making noise is the whole point.
What are some basic STEM activities for kids?
The pepper bowl and the penny drops are where we’d start any five year old. Each uses two or three things from the kitchen and shows exactly one idea, and the flipping arrow and estimation jar are just as simple.
What are some cheap and fun STEM activities for kids?
Most of the ones in this article cost nothing, because they use things you already have. A box of coffee filters and a bag of balloons are about the only things you might need to buy.
What are some 30 minute STEM activities for elementary school students?
Teachers with a class period of about 45 minutes can fit the paper columns, the index card puzzle, or the robot game and still have time to talk about results. Marker chromatography and the rubber band guitar work too, as long as the supplies are set out before the bell.
What are 100 easy science experiments I can do at home?
You could find 100 online in an afternoon, but most families end up repeating the same five or six favorites. We’d rather see a kid run the penny test three different ways than skim fifty ideas, and their own questions usually point to the next experiment.
What are some STEM hobbies for kids?
We’d look for a hobby your kid can keep getting better at for years, the way coding or model building works. 3D printing belongs in that group, and kids 9 and up who want to design their own parts can grow into the AOSEED X-MAKER for older makers.
What are good STEM fair projects?
The best fair projects test something that can be measured more than once. Comparing paper column shapes with a stack of books, timing ramp races on three surfaces, or counting penny drops with and without soap would each make a solid entry, since the results fit on a simple chart.
What are some STEM activities for students?
With a group, the robot game works especially well, because one kid writes the program and another has to follow it exactly. The column challenge and the estimation jar also turn easily into a class contest with a scoreboard on the whiteboard.
Further reading
3D Printed Puzzles for Kids by Age: 9 Projects From Shape Boards to Puzzle Boxes
15 Easy STEM Activities for Kids Using Things You Already Have
Is a 3D Printer a Good Gift for a Kid? A 10 Point Christmas Checklist for Age, Cost, and Space
