What you will need
- Pictures of the first and second Elephant Islands on pages 29/30 and 37/38,
- Foam bricks or cardboard boxes or small blocks/shapes, smaller brick, box or shape to represent the rock
- Elephant, mouse, dog, crocodile or other animals/figures
- Civil engineer poster
Duration
- 10 – 15 minutes
Investigate how to balance and fasten structures to stop them from falling down.
Early Learning Goal links
- Mathematics ELG: Numerical Patterns
- Understanding the World ELG: Past and Present
- Understanding the World ELG: People, Culture and Communities
- Understanding the World ELG: The Natural World
- Expressive Arts and Design ELG: Creating with Materials
Characteristics of effective learning
Our EYFS units provide enabling environments with teaching and support from adults. Reflecting on the characteristics of effective teaching and learning, children will have opportunity to learn and develop by:
• playing and exploring – children investigate and experience things, and ‘have a go’
• active learning – children concentrate and keep on trying if they encounter difficulties, and enjoy achievements
• creating and thinking critically – children have and develop their own ideas, make links between ideas, and develop strategies for doing things
Taken from Statutory Framework for the Early Years Foundation Stage.
© Crown copyright 2023 licensed under the terms of the Open Government Licence v3.0.
STEM vocabulary to introduce
balance, stable, unstable, wobbly, structure, fasten, tie, stick, join, big, bigger, small, smaller, large, larger, tall, taller, short, shorter, wide, wider, narrow, narrower
Before you start
Show the children the civil engineering poster and tell the children that they are going to be civil engineers for this activity.
Ask the children if they know what a civil engineer does. Civil engineers plan, design, build and manage the construction and upkeep of buildings and other structures such as roads, bridges, dams, water and sewerage systems, railways, airports and harbours.
Civil engineers are:
Creative when they plan and design buildings and structures,
Collaborative as they work together with other professionals to complete projects.
Resilient because their designs can be tricky to get right the first time.
Tell the children that for this activity they are going to be creative and resilient problem solvers.
You could read Balancing Act by Ellen Stoll Walsh to introduce the idea of balancing.
What to do – step 1
Ask the children to balance on one foot. You could ask:
- Is it easy or difficult?
- Is it harder than standing on two feet? Why?
- What do you need to do to stop yourself falling over?
Step 2
Show the children pictures of the first and second Elephant Islands on pages 29/30 and 37/38. You could ask:
- What is the structure balancing on?
- Do you think a huge structure like that can balance on a tiny rock?
- Shall we try?
Step 3
Ask the children to try to pile larger bricks/boxes shapes onto a small base.
- What happened?
- Why did your structure fall down?
You could try a using a long, flat cuboid shape like the see-saw in the story and balance blocks on top of this.
- What happens to the cuboid?
- Can you build on top of it when it is slanting towards the ground?
- What happens to the blocks?
Ask the children to investigate putting bigger blocks onto smaller blocks, and smaller blocks onto larger ones.
Which works best for building?
Other things to try- how high can you build your island?
Ask the children if they can make their island higher. Do they think they can get it to reach the ceiling/sky?
- What happens when we try to make out island higher and higher?
- Does it topple over? Why?
- What could we do to stop it falling over?
Remind the children about putting the bigger, heavier blocks at the bottom and smaller, lighter blocks at the top.
You could encourage the children to stack the blocks in different patterns. You could look at the patterns of bricks and blocks in your building.
Other things to try- building using a stable base
With the children, discuss whether the rock from the pictures (first and second Elephant Islands on pages 29/30 and 37/38) is a good base for building on.
- Do you think you will be able to balance a large structure on that small rock?
- What could you do to make your structure more stable/less wobbly?
Encourage the children to investigate using different sized bases. You could model this or provide different sized blocks or boxes. You could test different arrangements of the same blocks. Remember to encourage the children to build out as well as up. You could ask:
- Do you think you should build a large base for your island or a small one? Why?
- Which size base makes the structure less wobbly/more stable/stops your structure from falling down so easily?
- Could you make your base wider/bigger/longer?
- Does that work better? Does that make your island more stable?
- What is the best way to arrange your blocks for building?
Other things to try- fastening your island together
Look again at the picture of the Elephant Island. You could ask:
- How do you think all these parts/components stay on Elephant Island?
- Why don’t they fall off?
- How could you fasten parts of your Elephant Island together?
You could try fastening your island together using tape, string or rope. Support the children to fasten their structure together effectively. Using junk modelling materials and tape is the easiest way of fastening, while using string or rope will require a great deal of collaboration and resilience to be successful. You could ask:
- Why is it tricky to fasten Elephant Island together with glue?
- What else do you think you could fasten to Elephant Island now?
Other things to try- balancing more weight on your island
You could use a variety of shapes, sizes and weights of animals or figures for this balancing activity.
Tell the children that the animals/figures need to be able to go onto Elephant Island. You could ask them:
- Where should this animal go on the island? Why?
Try placing the animals in different positions on the island.
- Where should we put the heavier animals?
- Where should we put the lighter animals?
- Does the island topple over?
- What happens if we put all of the animals on one side of the island?
- Do we need to balance the island by spreading out the weight of the animals?
Remember to refer to the children as civil engineers and praise them for using the attributes. You could say things like:
“You have been creative in the way you have built different islands”
You were resilient when your island fell down and you built it back up again in a different way.”
The science of balancing and fastening
We have put together some useful information about the science of balancing and fastening to accompany this activity. Don’t worry, this is for your information only and to help you answer any questions children may have. We don’t expect you to explain this to the children in your setting!
Why do our towers of blocks topple over?
The centre of gravity of an object is the point that an object’s weight will balance around. Imagine balancing a ruler on the end of your finger without it falling off – your finger is in line with the centre of gravity. If you place the book or ruler onto a table with the centre of gravity off the edge of the table, it will fall. For symmetrical solid objects, the centre of gravity is in the middle of the object.
If a tower is built upright on flat ground, the centre of gravity is directly above the centre point of the base so the tower is very stable.
If a tower is built on sloping ground, the centre of gravity is no longer above the centre of the base and the tower will be more unstable.
If blocks are stacked unevenly their centre of gravity will not be above the centre of the base and they are more likely to fall.
The higher you stack blocks, the higher the centre of gravity becomes. A 4 block tower will have its centre of gravity at 2 blocks, a 10 story tower will have its centre of gravity at 5 blocks. The higher the centre of gravity, the easier it is to tip it so that it is no longer directly above the base and it will tip.
Why is it hard to balance on one leg?
The centre of gravity of an object is the point that an object’s weight will balance around. For people, this point changes depending on your position (arms up, arms down, leaning to one side, turning a somersault). When you are standing up straight with both feet on the floor, your centre of gravity is approximately in the area behind your belly button. When you stand on one leg you change the position of your centre of gravity slightly. You need to wave and wobble your arms and other leg around until your centre of gravity is in position above the centre of the foot you are standing on. You will then be balanced and more stable.
Why does building a wider base help us build bigger islands?
Objects with a wide base are more stable than objects with a narrow base. This is because it’s more likely that the centre of gravity will be directly above the base of the object. Blocks need to be stacked so their centre of gravity is above their base in order not to fall. If you put a cuboid shaped block on the floor horizontally, has a wide base relative to its height so it won’t tip over if you push on its side with your finger. It has a low centre of gravity. If you stand the same block vertically on one end the base is now narrower compared to its height and it has a higher centre of gravity. If you push the block near the top, it will probably fall over.
If you add more blocks, stacking them horizontally will create a more study structure with a lower centre of gravity. If you stack them vertically, they will have a higher centre of gravity which can be more easily tipped out of line with their base and fall down.
How do we balance the different blocks on our islands?
When we add the new blocks to our structures, we are changing the position of the centre of gravity of our structure. If we choose to put a heavy object at the top of a tower of blocks, the centre of gravity is higher up. This makes it easier for the tower to tip because that the centre of gravity is no longer above its base, and the tower falls down. If we place heavier objects lower down on our structures and lighter objects towards the top, the centre of gravity is lower and the structure is less likely to topple.
How does changing the stacking pattern help us to build higher towers?
If you look at brick walls you will see that bricks are laid in different patterns. These patterns are called bonds.
The weakest bond is stack bond pattern where the bricks are laid directly on top of one another vertically down the wall. A single vertical stack is not connected to the other stacks, so it could fall over easily if a crack developed in the mortar. If you stack your blocks like this, you will see they fall down easily.
The most common brick pattern we see is the stretcher bond pattern. This is laid with a brick placed halfway over the joints of the bricks in the row below. This interlinking pattern makes a stronger wall.
English bond brickwork combines alternate courses of placed lengthways and sideways. This traditional pattern is considered to be one of the strongest bonds as the bricks interlink more. It is commonly used for bridges and engineering projects. This is particularly effective if you are using foam bricks to build a tower!
Why does fastening our structures together make them stronger?
Fasteners ensure that materials are securely joined together. They help structures withstand the loads and forces placed upon them.
Fasteners reinforce and strengthen connections between the parts of the structure. They providing additional support and ensure that the structure is more stable over time. Examples of fasteners include nails, nuts and bolts, screws, rivets and anchors.
