Lesson 2: Compressing images

Pupils discover different image formats and learn why some are more appropriate for images sent from Mars, learning how compression works at a basic level

Before the lesson

Download classroom resources

Learning objective

  • To explain how the data for digital images can be compressed

National curriculum links

Pupils should be taught to:

  • Understand computer networks including the internet; how they can provide multiple services, such as the world-wide web, and the opportunities they offer for communication and collaboration


Success criteria

Cross-curricular links

Attention grabber

Main event


Pupils needing extra support: Work in partners and observe the more able partner. Then switch after the more able partner has completed, enabling the less able partner to understand what is required of them.


Pupils working at greater depth: Should experiment with the possibilities of the style of presentation and use Excel to help them to calculate exactly how many bits there are in each version of the image.

Wrapping up

Assessing pupils' progress and understanding


Created by:
Richard Williams,  
Computing specialist
Richard is a Year 6 Teacher at St. Pancras Primary School. Richard’s passion for teaching was recognised when he received Suffolk’s ‘Raising The Bar’ award for Innovation 2016. With his class he made the world’s first guided VR:360 school tour…
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