Target: construct and read Card A's discrete PPF; identify both axes and its fixed-input assumption. Prepare: Card A and frontier aid. Use words/raised strips if graph access is difficult.
- Launch · 2 min. Ask whether a table of maximum feasible pairs is a record of what people demand.
- Model · 4 min. Horizontal axis = repair workshops (0–4); vertical axis = reading circles (0–12). Plot (0,12), (1,11), (2,9), (3,6), (4,0) and join for a classroom sketch. Name ceteris paribus: other relevant inputs and the technique are held constant in this model. Say the smooth line between discrete pairs is illustrative, not observed in-between output.
- Guided reading · 5 min. At 2 workshops, maximum circles = 9. Ask why (2,6) can occur but is not on the maximum frontier; discuss underused modeled capacity, not an observed cause.
- Practice route · 7 min. Choose Day 6 route; graph or order all five coordinate pairs and attach an assumption label.
- Audit · 4 min. Partner labels circles on the horizontal axis or calls (3,9) feasible. Learner repairs axes and points to the maximum 6 circles at 3 workshops.
- Exit · 3 min. “What does a point on this frontier mean?” Key: maximum combination given stated fixed inputs/technique, not a value judgement.