Lesson Plan

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Lesson Plan
Grade: Year 12 Date: 17/01/2026
Subject: Economics
Lesson Topic: diminishing marginal utility
Learning Objective/s:
  • Define total utility and marginal utility and explain their relationship.
  • Describe the law of diminishing marginal utility and identify its key stages.
  • Interpret numerical tables and graphs that illustrate diminishing marginal utility.
  • Apply the equi‑marginal principle to allocate a fixed budget across two goods.
  • Evaluate how diminishing marginal utility underpins the downward‑sloping demand curve.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Printed worksheet with utility table and graph tasks
  • Calculator for each student
  • Sticky notes for quick polls
 Introduction:
Ask students to recall the last time they ate more than one slice of pizza and how their enjoyment changed.
Link this to their prior knowledge of utility and demand.
Explain that today they will be able to describe diminishing marginal utility and sketch its graph as evidence of success.
Lesson Structure:
  1. Do‑now (5’) – Think‑pair‑share on personal experience of consuming multiple units.
  2. Mini‑lecture (10’) – Define total and marginal utility; present the law of diminishing marginal utility.
  3. Guided analysis (12’) – Work through the pizza table, calculate MU, locate where MU = 0.
  4. Graphing activity (10’) – Students plot TU and MU curves; teacher provides feedback.
  5. Application discussion (5’) – Connect MU to the equi‑marginal principle and the shape of the demand curve.
  6. Exit ticket (3’) – Write one sentence answering: “Why does MU eventually become negative?”
Conclusion:
Summarise that diminishing marginal utility explains why total satisfaction peaks and why demand slopes downwards.
Collect exit tickets and remind students of the homework: complete a worksheet extending the utility table to a second good and write a short paragraph on how the law influences pricing decisions.