Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Chemistry
Lesson Topic: Describe the use of NPK fertilisers to provide the elements nitrogen, phosphorus and potassium for improved plant growth
Learning Objective/s:
  • Describe the role of nitrogen, phosphorus and potassium in plant growth.
  • Explain how NPK fertilizer ratios are expressed and interpreted.
  • Compare typical NPK ratios and match them to appropriate crop requirements.
  • Calculate the amount of a specific NPK fertilizer needed for a given nutrient target.
  • Assess environmental impacts of improper NPK use and propose mitigation practices.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides on NPK concepts
  • Sample NPK fertilizer packets or images
  • Worksheet with ratio interpretation and calculation exercises
  • Calculator for each student
  • Printed soil‑test result examples
 Introduction:
Begin with a quick poll: which nutrients do you think are most important for a healthy garden? Review prior knowledge that plants need nitrogen, phosphorus and potassium. Explain that today they will learn how these nutrients are combined in NPK fertilizers and how to choose the right ratio for different crops. Success will be demonstrated by correctly interpreting a fertilizer label and performing a simple application calculation.
Lesson Structure:
  1. Do‑now (5') – Students list the three macronutrients and their functions on sticky notes.
  2. Mini‑lecture (10') – Present the NPK concept, ratio notation, and typical uses with slides.
  3. Interactive activity (12') – In groups, match given NPK ratios to crop scenarios using a worksheet.
  4. Guided calculation (10') – Demonstrate the 20‑10‑10 example; students then solve a similar problem individually.
  5. Environmental discussion (8') – Discuss leaching, runoff, and best‑practice measures; record key points on the board.
  6. Check for understanding (5') – Quick quiz (Kahoot or show of hands) on definitions and ratio interpretation.
  7. Summary & exit ticket (5') – Students write one takeaway and one question on an index card.
Conclusion:
Recap the three nutrient roles, how NPK ratios guide fertilizer choice, and the importance of correct application rates. Collect exit tickets to gauge understanding and assign a short homework: research the NPK label of a fertilizer used at home and suggest an appropriate crop. Remind students to consider environmental safeguards when planning fertilizer use.