Target: distinguish relative scarcity from an absolute absence and identify who chooses and what is forgone. Prepare: Cards B/D and scarcity ledger aid.
- Launch · 2 min. Read B's two Saturday tasks. Ask whether eight staff-hours can be assigned to both tasks in full.
- Model · 4 min. Write
available: 8 staff-hours;possible uses: catalogue or help;constraint: same hours cannot do both at once. Relative scarcity means limited resources against competing uses, not that there are zero books or zero helpers. - Guided reading · 5 min. In D, identify the council as chooser, one project of crew capacity and the alternative project. Check that learners do not infer which project users prefer.
- Practice route · 7 min. Choose Day 1 route. Produce two constraint/chooser/alternative triples, one from B and one from D.
- Audit · 4 min. Partner claims “the council has no resources.” Repair to “enough crew time for one small project; choosing one forgoes the other.”
- Exit · 3 min. “Does scarcity mean nothing exists?” Key: no; the available inputs are insufficient for all competing uses at once.