LNF Cymru Literacy and numeracy for Wales

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GCSE Computer Science

Numeracy is heavy and specific: learners convert between denary, binary and hexadecimal, add in binary, work with base 2 storage units, calculate image, sound and compressed file sizes and routing costs, and reason with truth tables and DIV and MOD. Literacy centres on close reading of the Unit 2 scenario and requirements, precise technical vocabulary, short and extended judgement answers in Unit 1, and code annotation and test commentaries. The single biggest thing Key Stage 3 should build is fluent place value in base 2 and base 16, so that storage and file size calculations become routine.

Awarding body
WJEC
Level
Level 1 and Level 2
First taught
September 2025
Amount of literacy work
Medium
Amount of numeracy work
High
Specification
Open the specification
How this qualification is assessed
  • Unit 1: Understanding Computer Science: Digital examination 1 hour 30 minutes, 50%, 80 marks
  • Unit 2: Computer Programming: On-screen examination based on a pre-released brief, 2 hours, 50%, 80 marks, set and marked by WJEC

Skills that use Proofreading, editing and improving

  1. Annotating code, writing test commentaries and refining

    Assessed: In the exam

    Learners annotate code so a competent third party can follow it, present test outcomes with commentaries, and explain and evaluate the changes they make when refining a solution. Test plans must use typical, extreme and erroneous data.

    Literacy: Proofreading, editing and improving, Planning and organising for different purposes, audiences and context, Vocabulary, spelling, grammar

    Getting pupils ready

    Year 7
    Pupils add comments to their Scratch or Python game explaining what each part does, then swap with a partner who checks the comments make sense without running the code.
    Year 8
    Pupils complete a test table for a number-guessing program using typical, extreme and wrong inputs and write one sentence explaining each result.
    Year 9
    Pupils fix a bug in a given Python program and write a short commentary saying what went wrong, what they changed and how they retested it.
    Show the specification wording and the LNF statements

    Where it is in the specification: Unit 2, Sections 2.3.1 and 2.4.1, pages 25 to 26

    “present test outcomes with detailed and informed commentaries”
    Progression step 3

    • I can reflect on, edit and redraft to improve the quality of my expression, and use a range of strategies to ensure greater clarity.

    • I can explore different ways to plan, draft and present my work appropriately.

    • I can present my work appropriately in digital contexts.

    Progression step 4

    • I can improve writing through independent review and redrafting.

    • I can select and use appropriate strategies to plan and develop my writing for different purposes and audiences.

    • I can present my work appropriately in digital contexts using appropriate digital conventions, e.g. thumbnails, language preferences.

    Progression step 5

    • I can improve the content, structure and accuracy of my writing through critical reflection, review and editing, responding constructively to feedback.

    • I can summarise confidently, adapting style and form for the reader or intended audience and purpose for writing.

    • I can understand and use formal conventions of language in a range of purposes, making effective use of reference tools and accuracy aids.

Good to know

Links with other qualifications

Place value, powers, ratio and percentage reduction are taught in Mathematics, so agreeing shared language (for example 'column value' and 'simplest form') with the Mathematics department in Years 7 to 9 will help pupils transfer these skills to binary and file size work.

Source: WJEC GCSE Computer Science specification, teaching from 2025, for award from 2027, Version 3, September 2025.