Lesson 1: Decomposition and pattern recognition
Using decomposition and pattern recognition to solve problems.
Learning objective
To apply decomposition and pattern recognition to solve problems.
Success criteria
I can break a task into smaller, manageable parts.
I can identify patterns in similar tasks or problems.
I can explain how patterns help solve problems.
Before the lesson
Watch
- 3656 views
Watch
- 3656 views
Lesson plan
Before starting this unit, check the children can recall:
Decomposition is breaking something down into smaller chunks.
A code is a set of instructions that tell a computer what to do.
Debugging is the process of fixing code when it does not work.
Before starting this unit, check the children can recall:
Decomposition is breaking something down into smaller chunks.
A code is a set of instructions that tell a computer what to do.
Debugging is the process of fixing code when it does not work.
Optional: provide each child with a copy of the Knowledge catcher (see link: Assessment- Computing Y4: Computational thinking) and ask them to complete it to the best of their ability. Explain that at the end of the unit, they will revisit it, adding more information in a different colour.
Hand out the pre-cut, mixed-up pieces from the Activity: All jumbled up! to each table. Explain that the children need to put the pictures back together before the timer runs out. Explain that the image is divided into groups: A and B. They must first sort the pieces into As and Bs, assemble the As and then the Bs and combine both to form the complete picture. Set a suitable time using an online timer (no longer than five minutes).
Allow time for the children to assemble the pictures and ask:
Optional: provide each child with a copy of the Knowledge catcher (see link: Assessment- Computing Y4: Computational thinking) and ask them to complete it to the best of their ability. Explain that at the end of the unit, they will revisit it, adding more information in a different colour.
Hand out the pre-cut, mixed-up pieces from the Activity: All jumbled up! to each table. Explain that the children need to put the pictures back together before the timer runs out. Explain that the image is divided into groups: A and B. They must first sort the pieces into As and Bs, assemble the As and then the Bs and combine both to form the complete picture. Set a suitable time using an online timer (no longer than five minutes).
Allow time for the children to assemble the pictures and ask:
- How did breaking the problem up help? (The children may suggest that it helped them focus and that finishing small parts made solving the whole task easier.)
- What patterns or similarities did you notice that helped you decide where each piece went? (The children may suggest that they saw shapes or colours that matched.)
Explain to the children that the puzzle required them to break the larger problem (assembling the complete image) into smaller, manageable tasks. Discuss how, instead of working on the entire image at once, they focused on two sections (A and B) and solved each section individually before combining A and B to produce the completed picture. Introduce the word decomposition, explaining that it means breaking a problem into smaller parts.
Introduce the term computational thinking and explain to the children that it is a way of solving problems using different skills to help break down and organise a task. Inform them that it helps us approach problems logically, making them easier to understand and solve. Explain that people use this way of thinking in computing and everyday life, from planning a trip to solving a maths problem.
Inform the children that decomposition is one of these skills.
Watch the Pupil video: What is decomposition?
Pupil video: What is decomposition?
2535 views
Ask the children:
- How was the puzzle activity similar to the examples in the video? (Encourage the children to recognise that all involve breaking down a task into smaller, more manageable parts.)
- Can you think of other times you have used decomposition? (The children may give examples from everyday life, e.g. completing homework.)
- Why do you think decomposition is useful when writing computer programs? (The children may suggest that writing a whole program at once would be confusing and difficult. Breaking the task into smaller parts makes it easier to focus on each step, find mistakes and put everything together correctly.)
Set up the four activities across four tables (see Teacher knowledge). Ensure each table has the correct page from the Resource: Carousel instructions. Place the relevant equipment at each station:
A small model made from building blocks and a selection of building blocks to recreate it (this does not need to look like the model in the presentation).
- The Resource: Scrambled stories pre-cut and mixed up.
- The Resource: Map it out (one per group) and the Resource: Map it out directions.
A selection of classroom items to sort into categories.
Explain to the children that, in addition to decomposition, they will also use pattern recognition in this lesson. Highlight that they applied this skill while reassembling the puzzle earlier, looking for patterns and similarities to determine where the pieces fit, such as grouping similar sections (e.g. blue sky pieces or edges).
Watch the Pupil video: What is pattern recognition?
Revisit slides 1–4 of the Presentation: Carousel activities and click to reveal the skills used in each activity.
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In this unit
Assessment – Computing Y4: Computational thinking
- Current lesson
Lesson 1: Decomposition and pattern recognition
Lesson 2: Abstraction
Lesson 3: Algorithm design
Lesson 4: Computational thinking in action
Lesson 5: Evaluating computational thinking
