طرح درس ۹۰ دقیقه‌ای از روی یک هدف

Design a 90-minute lesson plan for the learning objective:
"[objective]"

Output blocks with timing:

- 0-10 min: Hook — a question or scenario that makes the
  topic feel necessary.
- 10-40 min: Core concept — explanation with one worked example.
- 40-65 min: Active practice — a problem learners solve in pairs.
- 65-80 min: Discussion — what was hard, where intuition broke.
- 80-90 min: Exit ticket — a 3-question check that reveals
  whether the objective was met (no fill-in-the-blanks; require
  the learner to apply the concept).