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Cross Curricular Maths

Maths in model making

Use scale, ratio, measurement, symmetry and 3D shape in miniature builds.

Quick answer

Maths in model making helps you build smaller versions of real things using scale, ratio, measurement, symmetry, and 3D shapes – like making a tiny house, car, or castle that looks just like the real one!

Learning outcome

By the end of this page, you will be able to use maths to plan and build a small model that shows the correct size, shape, and design of a real object. Success signs:
  • You can measure and draw a small version of a big object
  • You can use ratios to make sure your model is the right size
  • You can spot and use symmetry in your build
  • You can describe 3D shapes in your model

Why this matters

Maths helps you build things that look real and work well – from tiny toy cars to giant LEGO castles. When you make models, you use maths to make sure everything fits together, looks right, and is the correct size. This skill helps you in many jobs like architecture, engineering, and even video game design.

How it works

Making a model uses many maths ideas:
  1. Scale – This means how big or small your model is compared to the real thing. For example, a 1:10 scale means 1 unit on your model equals 10 units on the real object.
  2. Ratio – This compares two amounts. For example, if your model car is 10cm long and the real car is 2m long, the ratio is 10cm : 200cm or 1:20.
  3. Measurement – You need to measure length, width, height, and angles to build your model.
  4. Symmetry – This means one side of your model looks like the other side. Like a butterfly or a house with a roof in the middle.
  5. 3D shapes – Your model will use cubes, cuboids, pyramids, cylinders, and other 3D shapes to look realistic.

Examples you can see

Let’s imagine you are building a model of a house. Here’s how maths helps: Example 1: Scale You decide to make your model house at a 1:20 scale. That means:
  • Every 1cm on your model house equals 20cm on the real house.
  • If the real house is 6m wide, your model will be 30cm wide.
Example 2: Ratio You measure the real house and find:
  • Height = 4m
  • Width = 6m
  • Length = 8m
Your model house should be:
  • Height = 20cm
  • Width = 30cm
  • Length = 40cm
Example 3: Symmetry If your house has a front door and two windows, it should look the same on both sides. This is symmetry. You can check by folding the drawing in half – the two sides match. Example 4: 3D shapes Your house might use:
  • A cuboid for the main body of the house
  • A pyramid for the roof
  • A cylinder for a chimney
  • A cube for a window

Try it as a mini adventure

Adventure: Build a Model Castle! You are a young architect building a castle for a school project. You have a real castle to look at, and you must make a model that shows the correct size and shape.
  1. Step 1: Measure the real castle.
    • Height = 12m
    • Width = 10m
    • Length = 8m
  2. Step 2: Choose a scale.
    • Let’s use 1:50 scale. This means 1cm on your model = 50cm on the real castle.
  3. Step 3: Work out the model size.
    • Height = 12m = 1200cm → 1200 ÷ 50 = 24cm
    • Width = 10m = 1000cm → 1000 ÷ 50 = 20cm
    • Length = 8m = 800cm → 800 ÷ 50 = 16cm
  4. Step 4: Draw your castle using 3D shapes.
    • Main body = cuboid
    • Roof = pyramid
    • Towers = cylinders
    • Windows = cubes
  5. Step 5: Check for symmetry.
    • Draw a line down the middle of your castle. Both sides should look the same.

Common mistakes

  • Mistake: Forgetting to use the same scale for all parts.
    • Why it happens: Kids might measure one part with a 1:10 scale and another part with 1:20.
    • Fix: Always use the same scale for the whole model. Write it down!
  • Mistake: Mixing up centimetres and metres.
    • Why it happens: Confusing 1m = 100cm and using the wrong one.
    • Fix: Always double-check that you are converting correctly. 1m = 100cm, so 12m = 1200cm.
  • Mistake: Not checking symmetry.
    • Why it happens: Thinking that the front and back don’t need to match.
    • Fix: Draw a line down the middle and check both sides are the same.
  • Mistake: Choosing 3D shapes that don’t fit.
    • Why it happens: Trying to make a round window with a cube.
    • Fix: Use the right shape for the right part – use a cylinder for a chimney and a cube for a window.

Parent and carer guide

As a parent or carer, you can help by:
  • Encouraging your child to measure real objects and then work out the model size
  • Using everyday items like boxes, cans, or blocks to show 3D shapes
  • Helping your child check symmetry by folding drawings or using mirrors
  • Letting them choose their own scale and object to model
  • Practising ratio and scale with fun examples like cooking or drawing maps
Remember: It’s okay if the model isn’t perfect. The most important thing is that your child is learning how maths helps them build things.

Practice questions

  1. If a real car is 4m long and you use a 1:10 scale, how long is your model car?
  2. What 3D shape would you use for a chimney? Why?
  3. Draw a symmetrical house. How can you check it is symmetrical?
  4. A real tree is 5m tall. If you make a 1:5 scale model, how tall is the model?
  5. Which scale is smaller: 1:10 or 1:50? Explain your answer.
Answers:
  1. 4m = 400cm → 400 ÷ 10 = 40cm
  2. A cylinder, because it is round and tall like a chimney.
  3. Draw a line down the middle. If both sides match, it is symmetrical.
  4. 5m = 500cm → 500 ÷ 5 = 100cm
  5. 1:50 is smaller because it means 1 unit on the model = 50 units on the real object, so the model is much smaller.

FAQ

What is a scale in model making?

A scale tells you how big or small your model is compared to the real thing. For example, 1:10 means 1 unit on your model equals 10 units on the real object.

How do I choose a scale?

Choose a scale that fits your space and materials. A 1:10 scale is good for small toys, while 1:50 is good for bigger models.

Can I use maths to make a model of anything?

Yes! You can make models of houses, cars, animals, castles, and even planets. Just use the right scale and shapes.

Why is symmetry important in models?

Symmetry makes your model look balanced and realistic. Real objects often look the same on both sides.

What 3D shapes should I use for a house?

Use cuboids for the walls, pyramids for the roof, cylinders for chimneys, and cubes for windows.