Lesson: algorithms, decomposition and anstraction

The lesson is suitable for KS3 / GCSE Computer Science.

• Starter, asking pupils to comment on an article about the impact of algorithms
• Presentation on what an algorithm is, giving examples of algorithms, different kinds of computer algorithms and how these sets of instructions can be developed into a program.
• Sample python programs supporting the presentation on algorithms
• Presentation on decomposition saying what it is, giving examples and looking at how decomposition can apply to programs effecting the way a person programs (eg functional programming)
• Task to decompose an authentication probem.
• Presentation on abstraction, looking at what it is, giving examples and considering what data can be removed as part of the abstraction process.
• The pupils are given a task to remove any unecessary detail from an algorithm.
• The pupils complete five abstraction questions .
• Plenary, the pupils split into pairs and are given a problem. One person explains in a series of steps how to solve the problem (decomposition), whilst the other person tries to intervene to remove any unecessary detail from the explanation (abstraction)
• Homework task on how to make toast breaking this problem down using decomposition / abstraction.