Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Computer Science
Lesson Topic: Calculate the file size of an image file and a sound file, using information given
Learning Objective/s:
  • Describe the concepts of bits, bytes, resolution, colour depth, sampling rate, and audio bit depth.
  • Apply formulas to calculate uncompressed image and audio file sizes from given parameters.
  • Convert calculated sizes between bits, bytes, kilobytes, and megabytes.
  • Evaluate the effect of compression ratios on file size.
  • Solve typical exam‑style problems involving image and sound file calculations.
Materials Needed:
  • Projector or interactive whiteboard
  • Printed worksheet with practice questions
  • Calculator or spreadsheet software
  • Sample image and audio files for demonstration
  • Whiteboard and markers
  • Laptop with presentation slides
 Introduction:
Begin with a quick question: How many photos or songs can fit on a typical USB stick? Review bits, bytes, and basic storage terminology, then outline today’s success criteria: students will accurately compute image and audio file sizes and explain the impact of compression.
Lesson Structure:
  1. Do‑now (5') – Students answer the opening question and list known storage units on sticky notes.
  2. Mini‑lecture (10') – Review key concepts (resolution, colour depth, sampling rate, bit depth) and present the two formulas.
  3. Guided example (12') – Work through the image file size calculation together, then the sound file size, highlighting conversions.
  4. Independent practice (15') – Students solve the three practice questions on the worksheet, using calculators; teacher circulates for support.
  5. Check for understanding (8') – Quick quiz via Kahoot or show‑of‑hands on common mistakes and compression effects.
  6. Summary & exit ticket (5') – Students write one correct calculation step and one takeaway on a slip before leaving.
Conclusion:
Recap the steps from identifying parameters to applying the formulas and adjusting for compression. Collect exit tickets to gauge mastery, and assign homework to calculate file sizes for a given set of image and audio specifications.