How to teach solving problems by decomposing them into smaller parts in Key Stage 2 Computing

Author: Estelle Ashman, Curriculum Content Developer

This month our 'How do I teach...' blog will focus on ideas of how you could teach students to solve problems by decomposing them into smaller parts.

This months National Curriculum strand: solve problems by decomposing them into smaller parts.

Common misconceptions

  1. This strand requires programming. There are a lot of brilliant unplugged activities that students can use to build their understanding of decomposition in an accessible way. There is no need for pupils to use programming to decompose a problem at KS2 - this is a programming skill that is introduced at KS3 and even at KS4 is still something that students can struggle with. Tangible, hands-on activities work much better for introducing this concept.
  2. Students need to understand what the word decomposition means. Although pupils should be introduced to the correct terminology at KS2, there is no requirement within the strand for students to be able to respond to the request to decompose something or explain what the term means - that's something that students will be introduced at GCSE.
  3. Problems need to be complex in order for students to be able to decompose them. Simple problems that pupils have come across at home are fine to demonstrate this concept - activities such as writing out the steps needed to make a cup of tea are a great beginner activity.

What resources do Digital Schoolhouse have to support the teaching of this strand?


  1. App in a Day This workshop teaches pupils how to develop a top-down design for an app of their own devising. Although normally taught at A-Level, this simple activity is a brilliant way of introducing decomposition to students by getting them to think about all the parts that should make up their app.
  2. Just Dance with the Algorithm. This workshop uses dance to teach students about algorithms. Pupils learn about decomposition by breaking down their own dance routine into the individual dance moves that, when performed in sequence, make up larger dance sequences.
  3. Part-baked Games: Chef’s Edition. This workshop teaches pupils how to develop a paper prototype for a game. Decomposition is covered by learners breaking down all of the elements needed to create a level of their game, including images, sound and how elements might be programmed.

Playful Computing Activities

The Computational Thinking Duck is a great activity to demonstrate decomposition - what is the smallest number of bricks do you need to build a passable duck? What bricks have been used to create the duck - make a list. 

And there you have it, three workshop suggestions and a playful computing activity to help you deliver the controlling or simulating physical systems strand from the Key Stage 2 National Curriculum for Computing. If you have any comments or queries about these resources, I'd love to hear from you - drop me an email at If you're not sure where these activities could fit into your curriculum or would like to see the resources in action first? You can book a free workshop with your local Schoolhouse.