Breaking down challenges with E.a.R.L

Decomposition is an important part the KS1 computing curriculum. The term ‘decomposition’ can be simply translated as; the process of breaking down problems into smaller, more manageable parts. It forms a section of the larger topic of ‘computational thinking’ which supports wider problem-solving skills within computing.

This short, adaptable activity is similar to the ‘Fixing bugs and debugging with E.a.R.L’ activity in that; it begins from a standard starting point, facing direction and has a target destination. In this activity, the groups or individual children (depending on how many E.a.R.L coding robots you’ve shared) should be tasked with breaking down challenges at the programming stage.


A simple challenge for decomposition with a coding robot

The challenge below has an exercise to get E.a.R.L from his starting point to the green square using the 2D shapes mat. One way for children to decompose this problem is shown by the two dotted white arrows in the image:

  • Stage 1 is the section from the starting position to the red rectangle
  • Stage 2 is the section from the red rectangle to green square

(Image from teacher’s guide P9 – may need creating/amending to suit blog)

This clearly isn’t the only solution to this problem and children should always be asked to actively find other ways to achieve the positive result. One solution could look like this, using the E.a.R.L sequencing cards:

(Image from teacher’s guide P9 – two blocks of 4 images)

The solution above makes E.a.R.L’s lights flash between the two parts of the program. This can be a helpful addition to the debugging process for children (when it comes to fixing any errors with the algorithm). It means you can ask the pupils; “did the error occur before or after the lights flashed?” leading them to narrow their debugging process down. The sound buttons can also be used in the same way.

This activity can be adapted and extended as far as your class are able to go, helping them to complete algorithm understanding in the KS1 computing curriculum. Play around and have some fun with E.a.R.L coding robots!


For everything you need to teach decomposition, you can see our entire E.a.R.L range here.

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