Algorithms. Full Lesson Pack. Worksheet + Homework + Answers. Includes Algorithm Efficiency

Full lesson pack with worksheet, homework and answers

Focus: Algorithm, instruction, sequence and efficiency

This is a complete, carefully structured lesson introducing KS3 / beginner students to the concept of an algorithm as a clear, step-by-step description of a process.

The lesson is designed for Key Stage 3 students and has been built to avoid overly simplistic or patronising examples. It builds strong conceptual foundations.

What this resource includes:

• Full PowerPoint lesson (explicit and suitable for revision)
• Student worksheet
• Differentiated homework task
• Full teacher answer sheet
• Teacher notes outlining structure, timing and pedagogy

Content covered:

• Definition of an algorithm
• The meaning of instruction and sequence
• Evaluating weak algorithms using technical vocabulary
• Writing clear, structured algorithms for real-world tasks
• Introduction to best case, worst case and average case
• Early thinking about algorithm efficiency

The lesson deliberately moves beyond “does it work?” to begin exploring “does it work well?”, using a structured search scenario to introduce efficiency in an accessible way.

Pedagogical approach:

• Explicit teaching of technical vocabulary
• Structured discussion and evaluation
• Scaffolded writing tasks
• Clear model answers
• Stretch through efficiency analysis

This lesson forms a strong foundation for later work on conditionals, loops, flow diagrams and programming in Python.

Suitable for:

1. Key Stage 3 Computer Science
2. Non-specialist teachers
3. Schools introducing algorithms before programming

All materials are editable.