Lesson Plan

• Describe how the number of firms in a market influences price, quality, consumer choice, and profit.
• Explain the mechanisms (price competition, product differentiation, entry/exit) that produce these outcomes.
• Apply the concept to calculate profit and identify the normal‑profit condition in a perfectly competitive market.
• Evaluate the implications for consumers, firms, and policy‑makers.

• Projector and screen
• Whiteboard and markers
• Printed worksheet with market scenarios and checklist
• Calculators
• Graph paper
• Handout summarising key mechanisms

Start with a quick poll: “How many different brands of bottled water can you name?” This activates prior knowledge about market variety. Explain that today’s focus is on how a high number of firms shapes price, quality, choice, and profit. State that by the end of the lesson students will be able to predict these effects and justify them.

1. Do‑now (5'): Students list brands of a common product and share results.
2. Mini‑lecture (10'): Present market structures and the four effects of many firms using slides.
3. Guided analysis (15'): Work through the bottled‑water cost example; calculate profit and discuss the normal‑profit outcome.
4. Group activity (15'): Teams analyse a new market scenario, complete the checklist, and justify impacts on price, quality, choice, and profit.
5. Whole‑class debrief (10'): Groups present findings; teacher links mechanisms to observed outcomes.
6. Exit ticket (5'): Each student writes one sentence explaining why economic profit tends toward zero when many firms compete.

Summarise that intense competition drives prices down, pushes firms toward higher quality and greater variety, and erodes economic profit to a normal level. Collect exit tickets to check understanding, and assign a brief homework: research a real‑world market with many firms and write a paragraph describing how the four effects manifest.