Lesson T1.1.1

T1.1.1 Computational abstractions of real-world systems Quiz: KS3 Computing, Unit 1

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T1.1.1, Computational abstractions of real-world systems: 20 multiple choice questions for the KS3 Computing (National Curriculum), Unit 1: Computational thinking and algorithms, written with Revision Ninja.

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The 20 questions

  1. What does abstraction mean in computational thinking?

    • Writing every step of a program directly in binary code
    • Keeping only the details needed to solve a problem and hiding the rest
    • Copying a real system into a computer without making any changes
    • Adding as much detail as possible so the model matches reality exactly

  2. Which of these is an example of abstraction?

    • A recording of every sound made in a school day, stored at the highest quality
    • A list of every brick used to build a house, along with the colour of its mortar
    • A London Underground map that shows lines and stations but not true distances
    • A full-scale photograph of a city street that records every window, sign and passer-by

  3. In a computational model, what is the state of a system?

    • The list of rules that decides how the model changes from one step to the next
    • The information that describes its condition at a particular moment
    • The speed of the computer that is running the model at a particular moment
    • The number of lines of code needed to write the model and its user interface

  4. Why do programmers build models of real-world systems?

    • To test and predict behaviour without building the real system
    • To remove the need for any input data at all
    • To guarantee that the real system will never change
    • To stop the real system from ever working again

  5. A traffic light model has the states red, amber and green. What is its behaviour?

    • The rules that decide when the light changes from one state to the next
    • The paint used on the light casing and the material of the lamp inside it
    • The colours that the light is able to show, such as red, amber and green
    • The height of the pole that the light is fixed to above the road surface

  6. A model of a lift ignores the colour of its doors. Why is this sensible?

    • A lift cannot be modelled at all unless its colour is recorded
    • The colour does not affect how the lift moves between floors
    • Colour is always the most important property of any model
    • Doors must always be modelled in full colour to be accurate

  7. A game models a football as a single moving point. What has been abstracted away?

    • The direction in which the ball is moving
    • The position of the ball on the pitch
    • The ball's shape, size and surface texture
    • The speed at which the ball is travelling

  8. A school timetable model stores what for each lesson?

    • The type of carpet fitted in each corridor
    • The make of whiteboard in each classroom
    • The room, the teacher and the start time
    • The colour scheme used on the school website

  9. A plant-growth model records height in centimetres and ignores leaf colour. What kind of choice is this?

    • Choosing to record every leaf in full detail so the model is as accurate as possible
    • Choosing which properties to keep so the model answers the question being asked
    • Choosing to measure the plant only once so the model can be run more quickly
    • Choosing to store each leaf as a separate picture in memory for later use

  10. A car covers 120 km in 2 hours. A simple speed model uses speed = distance divided by time. What speed does it give?

    • 30 km/h
    • 122 km/h
    • 60 km/h
    • 240 km/h

  11. A shop queue model has 12 people in it. 5 people are served. How many people does the model show now?

    • 12
    • 7
    • 17
    • 5

  12. Two models of the same bus route differ. One records every passenger's seat, the other only the number of passengers. What is the main difference?

    • Only the first model can be run on a computer, which is why it is more useful
    • The second model cannot store numbers, so it can only describe the route
    • They abstract different levels of detail for different questions
    • One model is wrong and the other model is right, so only one should be kept

  13. Why might a model be inaccurate even though it contains a lot of detail?

    • Detailed models are always inaccurate by their very nature
    • It may include irrelevant details or miss a rule that really matters
    • Computers cannot run a model that has more than ten rules
    • Models are not allowed to contain any numbers at all

  14. What is a variable used for in a model?

    • Storing a value that can change while the system runs
    • Fixing a value that can never change at all
    • Printing only the final answer at the very end
    • Drawing a picture of the system on the screen

  15. What does decomposition mean in computational thinking?

    • Testing a program with random data to find faults before it is shared with others
    • Breaking a large problem into smaller parts that are easier to solve
    • Deleting parts of a program that are not needed so it runs faster on a computer
    • Converting a program from text into binary code so it can be run on a processor

  16. A rainfall model uses one number for rain per hour and ignores where each drop lands. What is being abstracted?

    • The exact position of each raindrop
    • The total amount of rain that falls in an hour
    • The number of hours the rain has lasted so far
    • The rate at which the rain is falling each hour

  17. A museum app's map model stores only each exhibit's name, its icon and its position on the map. Which of these details is NOT stored in the model?

    • The exact size and materials used to build each exhibit
    • The icon that represents each exhibit on the map screen
    • The name that identifies each exhibit on the museum map
    • The position of each exhibit within the bounds of the map

  18. A supermarket checkout model tracks only queue length and items per customer. Which question is it best suited to answer?

    • How the shop building was originally constructed
    • How long customers are likely to wait in line
    • Which brand of carrier bag the shop uses
    • What colour the shop's signs are painted

  19. When designing a model, what should you decide first?

    • What colour the user interface should be
    • Which faster computer to buy for running it
    • What question the model must answer
    • Writing every line of the code in full

  20. A weather model stores the temperature once for each hour of the day. What is a benefit of this abstraction?

    • It stops the temperature from ever changing during the day
    • It removes the need for any temperature measurements at all
    • It needs less data and can still show how the temperature changes through the day
    • It guarantees an exact temperature reading at every single second

All KS3 Computing quizzes