Topic title: Data Representation
Year group: 9
When taught: September to December
What are we learning?
At the end of this unit all pupils should be able to:
• Define the terms bit, byte, kilobyte, megabyte, gigabyte
• Understand that data needs to be converted into a binary format to be processed
• Add two 8-bit binary integers
• Understand the term ‘character set’
• Understand how a bitmap graphic is made up of individual pixels
• Explain how each pixel is represented in binary
Most pupils will be able to:
• Define the terms nibble, terabyte and petabyte
• Convert positive denary whole numbers (0-255) into 8-bit binary numbers and vice versa
• Convert positive denary whole numbers (0-255) into 2-digit hexadecimal numbers
• Add two 8-bit binary integers and explain overflow errors which may occur
• Understand the use of binary codes to represent characters
• Understand the term ‘character set’
Some pupils will be able to:
• Convert between binary, denary and hexadecimal equivalents of the same number
• Understand that the number of bits per pixel determines the number of available colours
• Explain how sampling intervals and resolution affect the size of a sound file.
• Understand how sound is sampled and stored in digital form
Why is this important to know?
Learning Skills:
• Synthesis: Pupils will bring ideas together and create solutions/
• Calculations: when working out file sizes of images and music
Life Skills:
• Understanding how media used every day is recorded and stored digitally
• Preparing for the future – everything stored digitally.
ICT Skills:
• Software: Graphic design software such as Photoshop, audacity and Premier Pro.
• Microsoft Excel to demonstrate RGB values.
Literacy Skills:
• Vocabulary: Learning new vocab and learning how it links to other subjects such as science, maths, photography and music.
Where does this link into our past and future learning?
Pupils will have been introduced to the concept of binary conversions storage in Year 7 and 8. They will have an understanding of vectors and bitmaps and how images are stored in 0s and 1s.
Future learning topic: GCSE Computer Science – Data Representation
How will we be assessed on this topic?
• End of topic assessment – 40 questions all based on unit learning.
What makes a strong piece of work in this topic?
• Clear understanding and correct use of binary, denary, and hexadecimal number systems
• Accurate conversions between number systems (e.g. binary to denary, hex to binary)
• Correct answers with clearly shown working out, especially in binary arithmetic (addition and subtraction)
• Detailed explanations of how data like images and sound are stored using binary
• Use of key terms (e.g. bit, byte, sample rate, resolution, metadata, compression) confidently and appropriately
• Well-labelled diagrams or examples (e.g. how pixels represent an image or how sound is sampled)
• Demonstrated understanding of why data compression is important and how it works
• Neat presentation and well-organised layout to make your work easy to read
What are teachers hoping to see?
• Confidence in working with different number systems
• Ability to explain concepts in your own words
• Use of examples to support your understanding (e.g. showing how a character is stored)
• A mix of theory and practice – evidence of problem-solving and applied skills
• Correct terminology and definitions used throughout
• Understanding of the bigger picture – why data representation matters in real life
• Evidence that you have checked your work and made corrections where needed
What key words are there in this topic?
What can I try if I want to stretch and challenge myself on this topic?
• Learn and practise binary subtraction and even binary multiplication
• Research and explain Unicode and how it differs from ASCII
• Explore how colour images are stored (bit depth, RGB values)
• Compare lossy and lossless compression and give examples of each
• Investigate how sound quality is affected by sample rate and bit depth
• Try converting between all three number systems (binary, denary, hexadecimal
• Use Python or another programming language to create a simple binary converter tool
• Research how data is stored on physical devices like hard drives or SSDs
What wider reading can be done on this topic?
• CGP KS3 Computing Complete Revision & Practice
• Hodder Compute-IT: Computing for KS3
• PG Online OCR GCSE Computer Science
What websites are linked to the topic?
• BBC Bitesize (graphic design): https://www.bbc.co.uk/bitesize/search?q=graphic+design+ks3
• Website used for free graphic design software: https://inkscape.org/ or https://vectr.com/
• Website used for tutorials: https://www.photoshopessentials.com/
Careers
• Advertising designer
• Branding designer
• Creative director
• Editorial layout artist
• Game designer
• Games developer
• Graphic designer
• Marketing Director
• Package designer
• Software engineer
• Sound Engineer
• Typographer
• UX designer
• Web designer
Extra Skills:
• Communication
• Teamwork
• Problem-solving
• Time management
• Organisation
• Software Skills
Progression:
• Online tutorials
• Graphic design clubs
• GCSE Computer Science
• A-level Computer Science
• University/Apprenticeship
• Work experience
