Lesson Plan

• Calculate break‑even quantity, contribution per unit, total contribution and profit for a given set of cost data.
• Interpret margin of safety in both units and percentage and explain its significance.
• Construct and analyse a break‑even chart to visualise cost‑revenue relationships.

• Projector and screen
• Whiteboard and markers
• Calculator or spreadsheet software
• Printed worksheet with data tables
• Graph paper, rulers and coloured pencils
• Formula summary handout

Begin with a quick scenario: a company launching a new product wonders how many units must be sold to avoid a loss. Review students’ prior knowledge of fixed, variable costs and contribution. State that by the end of the lesson they will be able to compute break‑even, margin of safety and profit and illustrate these concepts on a graph.

1. Do‑now (5'): Recall quiz on fixed vs. variable costs and contribution.
2. Mini‑lecture (10'): Introduce formulas and explain each term using the Eco‑Bottles example.
3. Guided practice (15'): Step‑by‑step calculations on the worksheet; students complete each formula together.
4. Graphing activity (10'): Students draw the break‑even chart on graph paper, label BEQ, profit area and margin of safety.
5. Application questions (10'): Pair work on practice problem 1 and discussion of price‑change effects (problem 2).
6. Check for understanding (5'): Exit ticket – one sentence describing how a price increase shifts the break‑even point.

Summarise the key steps for calculating break‑even, margin of safety and profit and how the chart visualises these results. Collect exit tickets and assign homework: complete the remaining practice questions and submit a neatly drawn break‑even chart.