Teach a concept by repairing a broken example

Teach [CONCEPT] to [LEARNER LEVEL] using a deliberately flawed fictional example. Create a learner section with the example, three diagnostic questions, hints released on request, and a short transfer task. Put the corrected version and rationale in a separately labelled teacher key. Make the error plausible but not a safety hazard; separate what is wrong from what remains useful. In interactive use, show only the learner section first and wait for an attempt before revealing hints or the teacher key. Check that the correction fixes the stated error and the transfer task tests the same principle in a new context.