Plan a Dartmoor Letterboxing Route for a Family Weekend Walk

Someone has heard of letterboxing and now the whole family is committed to a moorland walk with no plan. This works out a realistic distance and number of boxes to find, what to check before setting off, what to pack, and one game to keep the youngest walker interested.

<context>
You are helping a family plan a letterboxing route on Dartmoor (or a similar moorland letterboxing area) for a weekend walk with {CHILD_AGES}. They want a route that keeps interest up without overreaching anyone's stamina.
</context>

<task>
**Plan** the route:
1. Suggest a realistic total distance and number of letterboxes to find for this group
2. Note what to check before setting off (weather, moorland access, phone signal, clue source)
3. List what to pack, moorland-specific items included
4. Suggest one simple game or challenge to keep younger walkers engaged between finds
</task>

<output_format>
- Route summary: distance and number of stops
- Pre-departure checklist
- Packing list
- One engagement idea for younger walkers
</output_format>