Lesson Plan

• Describe the purpose of denary, binary, and hexadecimal number systems.
• Explain how each base represents values using positional notation.
• Convert numbers between denary, binary, and hexadecimal using standard algorithms.
• Apply conversion techniques to solve typical IGCSE Computer Science problems.
• Evaluate why different bases are used in computing contexts.

• Projector and screen
• Whiteboard and markers
• Printed conversion worksheets
• Calculators
• Binary and hexadecimal reference cards
• Laptops or computers with a simple IDE/spreadsheet

Start with a quick poll: which number system do you use daily? Review that decimal is our everyday system and introduce binary as the language of computers. Outline today’s success criteria: students will be able to convert between decimal, binary and hexadecimal and explain why each is useful.

1. Do‑now (5’) – students complete a mini‑chart writing decimal equivalents for 0‑15; teacher checks.
2. Mini‑lecture (10’) – explain positional notation for decimal, binary and hex using the projector.
3. Guided practice (15’) – convert selected decimal numbers to binary via repeated division; pair work with teacher circulation.
4. Interactive conversion (10’) – binary to hex by grouping bits; demonstrate on the whiteboard.
5. Application activity (15’) – worksheet with mixed conversion problems, including colour codes and memory addresses.
6. Check for understanding (5’) – quick exit‑ticket quiz where each student writes one conversion method and its purpose.

Recap how each base serves a distinct role in computing and review the conversion steps. For the exit ticket, students note a real‑world example of using hexadecimal. Homework: complete the textbook conversion exercise set.