Finding STEM activities that actually work with 30 children, limited resources, and 45 minutes on the timetable is harder than it should be. Pinterest is full of ideas that look wonderful in a photo and fall apart in a real classroom. This list is different. Every activity here has been used in primary schools, requires minimal prep, and delivers genuine curriculum-linked learning.
We’ve organised them by subject focus, with estimated prep time and cost so you can pick what works for your situation.
Science-Focused Activities
1. Balloon-Powered Cars
Children design and build cars from cardboard, straws, and bottle caps, then power them with inflated balloons. It teaches forces, air resistance, and fair testing in a single session. Cost: under £5 for the whole class if you save cardboard tubes and boxes.
2. Egg Drop Challenge
The classic for a reason. Give each group a bag of materials (newspaper, tape, string, bubble wrap, a plastic bag) and one raw egg. They have 30 minutes to build a protective structure, then you drop them from the top of the climbing frame. Covers forces, materials, and properties of matter. Prep time: 10 minutes gathering materials.
3. Shadow Tracking
On a sunny day, children trace shadows of an object at hourly intervals. By the afternoon, they have concrete evidence of the Earth’s rotation. This works brilliantly as a whole-day activity running alongside normal lessons. Cost: chalk and a stick.
4. Seed Germination Experiment
Set up cress seeds in different conditions: light vs dark, warm vs cold, water vs dry. Children make predictions, record observations over a week, and draw conclusions. It covers working scientifically and plants in a single, low-maintenance investigation. Cost: £2 for cress seeds.
5. Water Filtration Challenge
Give each group dirty water (soil, leaves, food colouring) and materials to filter it: sand, gravel, cotton wool, coffee filters, plastic bottles. They design and test filtration systems. Links to properties of materials and real-world engineering. Prep: 15 minutes making the dirty water.
Technology & Computing Activities
6. Unplugged Coding with Grid Maps
Draw a grid on the playground or use a floor mat. Children write algorithms to guide a partner from start to finish using only “forward”, “turn left”, and “turn right” commands. It teaches sequencing and debugging without a single computer. Cost: nothing.
7. Scratch Animation Project
Children create a short animation telling a story linked to their current topic. A Year 4 class studying the Romans could animate a day in the life of a gladiator. Covers sequencing, loops, and events in Scratch while reinforcing cross-curricular knowledge. Needs: computers with Scratch installed or internet access.
8. Micro:bit Step Counter
If your school has micro:bits, children programme a simple step counter using the accelerometer. They test it, calibrate it, compare results, and discuss accuracy. It connects computing, maths (data handling), and PE. A 45-minute activity once children are familiar with MakeCode.
9. Binary Birthday Cards
Teach children how binary numbers work, then have them encode their birthday (or a secret message) in binary on a card. Punchable dots or coloured squares represent 1s and 0s. Covers data representation while producing something they want to keep.
10. Digital Photography Challenge
Give groups a tablet and a brief: photograph 10 examples of symmetry, patterns, or right angles around the school grounds. They curate their best 5 images and present them. Combines computing (digital literacy) with maths. Cost: tablets you already have.
Engineering & Design Activities
11. Spaghetti and Marshmallow Towers
Each group gets 20 sticks of spaghetti, one metre of tape, one metre of string, and one marshmallow. The marshmallow must sit on top of the tallest freestanding structure. Teaches structural engineering principles and iterative design. Cost: £3 for the whole class.
12. Bridge Building Challenge
Using newspaper and tape only, groups build a bridge between two tables that can hold a textbook. Covers beam, arch, and truss structures. Extend it by making them calculate load-bearing ratios. The competitive element keeps Year 5 and 6 fully engaged. Cost: old newspapers.
13. Catapult Construction
Lolly sticks, elastic bands, and a bottle cap make a surprisingly effective catapult. Children test how far it launches a pompom, then modify the design to improve distance. Covers forces, levers, and fair testing. Total cost: about £8 for 30 children.
14. Marble Run Design
Cardboard tubes, tape, and a marble. The brief: build a run that keeps the marble moving for the longest possible time. Groups iterate, test, rebuild, and compete. Teaches gravity, friction, and the design process. Save toilet roll tubes for a fortnight beforehand.
15. Wind-Powered Vehicle
Children build a small vehicle that moves using only wind power (a desk fan at one end of the hall). They experiment with sail shapes, sizes, and materials. Links to forces, air resistance, and renewable energy. Cost: card, straws, and wheels from construction kits.
Maths-Focused Activities
16. Playground Maths Trail
Set up stations around the school grounds where children measure, estimate, calculate, and record. Measure the height of the climbing frame using shadows and ratios. Estimate the number of bricks in a wall. Calculate the area of the football pitch. Real maths in real contexts. Prep: 20 minutes setting up station cards.
17. Stock Market Simulation
For Year 5 and 6, run a simplified stock market game over a week. Each group starts with £1,000 of imaginary money and buys shares in fictional companies. You update share prices daily based on “news events” you create. Covers profit, loss, percentages, and decision-making. Prep: moderate, but the engagement is exceptional.
18. Data Collection and Graphing
Children conduct a survey (favourite crisps, how they travel to school, shoe sizes in the class) and present the data as bar charts, pie charts, or line graphs. The key is making it their data about their lives. Use squared paper or Excel depending on your class. Cost: nothing.
19. Tessellation Art
Explore which shapes tessellate and why. Children create tessellation patterns inspired by M.C. Escher, starting with simple squares and building to modified shapes. Covers geometry, symmetry, and spatial reasoning while producing display-worthy artwork. Cost: card, scissors, coloured pencils.
20. Scale Model of the Solar System
Calculate the distances between planets at a chosen scale, then place markers around the school grounds. Children are always stunned by how far away Neptune ends up. Covers ratio, scale, and working with large numbers. Uses the playground or field. Cost: nothing.
Cross-Curricular STEM Activities
21. Weather Station Project
Build simple weather instruments (rain gauge from a plastic bottle, wind vane from card, thermometer readings) and collect data over a half term. Children record, graph, and analyse patterns. Covers science (weather), maths (data handling), and computing (spreadsheets). Ongoing but low daily effort.
22. Eco-Audit of the School
Children audit the school’s energy use, waste, and water consumption. They collect data, identify problems, propose solutions, and present findings to the head teacher. Real-world STEM with genuine impact. Year 6 often run with this one. Cost: nothing. Impact: potentially significant savings.
23. Rocket Design and Launch
Paper rockets launched from a stomp launcher (a plastic bottle and PVC pipe) let children test fin designs, nose cone shapes, and body length. They measure distance, record results, and optimise. Covers forces, fair testing, and data recording. A stomp launcher costs about £15 and lasts years.
24. Cardboard Arcade
Inspired by Caine’s Arcade, children design and build working arcade games from cardboard. Skee-ball, pinball, claw machines, basketball shooters. Then the rest of the school visits to play. Covers design technology, mechanisms, and teamwork. Perfect for the last week of term.
25. STEM Workshop Day
Sometimes the most impactful activity is one delivered by specialists with professional equipment. A robotics workshop where every child builds and programmes a robot. A drone flying session where they learn about aerodynamics and coding. An AI session where they train a machine learning model. These are experiences that are genuinely difficult to replicate with classroom resources alone.
Our STEM workshops cover robotics, drones, AI, cybersecurity, 3D design, and more. Every session is curriculum-linked, fully resourced, and delivered by DBS-checked specialists in your school hall. If you want to see what’s available and what it costs, our instant quote tool gives you a price in seconds. No chasing, no waiting, no hidden extras.
Making It Work in Practice
The biggest barrier to STEM activities is not money or equipment. It’s time. Teachers are stretched thin, and adding something new feels like adding something extra. But STEM activities do not need to be separate from the curriculum. The best ones replace a standard lesson rather than sitting on top of it.
A bridge building challenge is a forces lesson. A Scratch animation is a computing lesson. A tessellation project is maths and art. Frame them that way and they fit the timetable without anyone working overtime.
Start with one activity from this list. Run it with one class. See what happens. The children will tell you whether it was worth it. In our experience, they always do.
