Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Computer Science
Lesson Topic: Describe parity check (odd and even), checksum and echo check
Learning Objective/s:
  • Describe how even and odd parity checks detect single‑bit errors.
  • Explain the process of calculating and verifying a checksum.
  • Illustrate the echo (loopback) test procedure and its typical uses.
  • Compare the strengths and limitations of parity, checksum, and echo checks.
  • Apply each method to sample binary data to identify transmission errors.
Materials Needed:
  • Projector or interactive whiteboard
  • Slides with diagrams of parity, checksum, and echo checks
  • Worksheets containing binary examples
  • Computers with a simple programming environment (e.g., Python)
  • Handouts of sample data frames
  • Whiteboard and markers
 Introduction:
Begin with a quick demonstration: send a short binary message and intentionally flip a bit to show how errors appear. Ask students what they already know about error detection from previous lessons on data transmission. Explain that today they will explore three fundamental techniques—parity check, checksum, and echo check—and will be able to select an appropriate method for a given scenario.
Lesson Structure:
  1. Do‑now (5') – Short quiz on binary representation and prior error‑detection concepts.
  2. Direct instruction (10') – Explain even and odd parity, show examples, discuss detection limits.
  3. Guided practice (10') – Small groups calculate parity bits for given words and identify single‑bit errors.
  4. Checksum demonstration (10') – Walk through binary addition and one's complement using a three‑byte block; students complete a worksheet.
  5. Echo check activity (10') – Simulate a loopback test with two laptops; students send a frame and verify the echoed copy.
  6. Comparison discussion (5') – Whole‑class compare methods using the provided comparison table; highlight strengths/weaknesses.
  7. Formative check (5') – Exit ticket: choose the best error‑detection method for a described scenario.
Conclusion:
Summarise that parity checks are simple but limited, checksums catch many multi‑bit errors, and echo tests are useful for link diagnostics. Students complete an exit ticket stating which technique they would use for a given transmission case. For homework, they will write a short program that computes a checksum for any user‑entered binary string.