You’re a busy teacher (or parent) and you just don’t have time to spend hours prepping your STEM lessons every week! Lucky for you, we have a list of no-prep STEM activities right here that will help save your time and sanity in and out of the classroom.
So keep scrolling and get ready to find something else to do with your time after grabbing these low-prep STEM activity ideas!
And when you have a bit more time, don’t forget to check out our complete list of STEM activities for kids, easy STEM activities for elementary, STEM activities for kindergarten, and STEM projects for toddlers!

How No-Prep are These STEM Activities, Really?
These STEM activities for kids are about as no-prep as you can get. Most of the supplies required for these hands-on STEM activities are things you already have in the classroom.
And when you use our STEM challenge worksheet, you can save even more time in planning. Just print the worksheet, gather the supplies, and go!
Most of these low-prep STEM activities are child-led, which means the children are responsible for thinking of a solution to a problem.
Use these no-prep STEM activities to offer stem challenges about the weather, earth science, chemistry, engineering, math, physics, light, and coding.
How to do the No-Prep STEM Activities

For maximum benefit, you can create a scenario ahead of time that the kids can use their STEM activity to create a solution to. For example, kids could do the walking rainbow in a jar activity as a solution for how to get water from a low area to a high area, as might be required on certain farms.
Kids can do the paper airplane design challenge as an answer to the problem of what is the most aerodynamic shape for a real plane design.
Think of a problem, offer the no-prep STEM challenges as a solution, and let the kids solve the problems on their own. Since these are open-ended STEM challenges, kids can come up with their own answers.
The Complete List of No-Prep STEM Activities
Don’t have time for extended lesson planning? Try one of these low-prep STEM activities with your class!

No-Prep Weather STEM Activities
These STEM activities are all about weather.
Learn about capillary action with just water, food coloring, and paper towels.
Make your own snow storm in a jar and learn about weather patterns.
Learn about the water cycle and make your own cloud in a jar.
Learn how clouds work when you make a raining rainbow in a jar.
No-Prep Earth Science STEM Activities
Make earth science fun with these STEM activities.
Learn about salt crystals and ionic bonds when making salt crystal dinosaurs.
Testing the Strength of Spaghetti
All you need for this STEM challenge is spaghetti!
Hot and Cold Temperature Density Tower
Food coloring and water is all that is needed to make this density tower.
A tornado in a jar is one of the easiest STEM challenges to complete!
Saltwater Desalinization Experiment
See if you can remove salt from water and make it drinkable!
No-Prep Chemistry STEM Activities

Solve the problems of the world with chemistry!
If you have glue and borax, you can make this slime!
Vinegar and eggs are all that are needed to make this no-prep STEM activity.
With jars and sugar, you can learn about crystals and ionic bonds.
Did you know that you can use magnesium to make polymer chains?
Kids will love this low-prep STEM challenge activity making their own bouncy balls.
No-Prep Engineering STEM Activities
Nothing beats a classic engineering STEM challenge!
Protect eggs and learn about packaging design.
Cotton Swab Engineering Challenge
Use cotton swabs as building materials and recreate landmark bridges.
Paper Airplane Engineering Challenge
What is the best design for an airplane?
No-Prep Physics STEM Activities

Explore global physics with these activities!
Surface Tension Milk Experiment
All it takes is some milk, food coloring, and soap to complete this no-prep STEM challenge.
Learn about cartesian divers using a ketchup packet and plastic water bottle.
If you have a few common household materials lying around, you can make this liquid density tower.
No-Prep Light STEM Activities
Play with light in these no-prep STEM activities.
Bending Pencil Light Refraction Experiment
All you need is a pencil and a jar to learn about light refraction.
This electrical engineering STEM challenge uses Squishy Circuits!
Make your own constellations using paper and a flashlight.
No-Prep Math Activities

Try these fun STEM-inspired math challenges!
If you have a deck of Uno cards, you can play this math game.
Making a Mobius strip requires one piece of paper!
Use Geomotiles to create 3D geometry shapes.
With dice, you can practice multiplication.
Fractions can become art in this no-prep STEM challenge.
Learn about probability with a Venn diagram and a dice!
No-Prep Coding Activities for Kids
Nothing says STEM activities like coding, and these coding activities require almost zero prep from you.
These coding apps require no input from a teacher or parent.
Use these ready-to-go coding ideas for an Ozobot Evo.
Binary Secret Message Coding Bracelets
If you have beads, you can create the secret message coding STEM challenge.
What are your favorite no-prep STEM challenges?