Decode & Discover
Searching for Hidden Treasure
Explorers
Tucked inside a coral-crusted crate from the wreck of the HMS Endeavour, your students uncover a sealed tube and a weather-stained message—coded, mysterious, and signed only with a “C.” As they trace Captain Cook’s historic voyages across the globe, a deeper mystery begins to surface: Did the captain discover something so valuable he erased it from his maps? And if so… where is it now?
This globe-spanning challenge blends geography, logic, and cryptography. Students will chart real routes, decode encrypted clues, and follow the trail to a hidden island. Along the way, they’ll apply reasoning, pattern recognition, and historical inference—building the grit and determination worthy of explorers who never gave up the chase.
**To download the PDFs or Google Docs, you can find those links below the directions. There are full links for the teacher instructions as well as student hand-outs.
A 3-part Challenge
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Charting the Journey
It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.
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Decoding a message
It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.
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"X" marks the Spot
It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.
Decode & Discover: The Captain’s Code – Teacher Instructions
🧭 Step 3: The Island Puzzle (Logic Grid Challenge)
🎯 Overview:
This logic puzzle challenges students to match four islands with four hidden treasures and their unique hiding spots. It encourages deductive reasoning, inference, and systematic elimination, all wrapped in the thematic narrative of Captain Cook’s mysterious legacy.
📝 Objective:
Students will use a set of narrative clues to fill in a logic grid and determine which treasure is hidden in which location on each island.
🧰 Setup Tips:
Review the background story and clue list as a class.
Display a sample 3x3x3 logic grid and solve it together (see example below).
Model how to use “X” to eliminate and “O” to confirm options.
Emphasize one-to-one relationships: each island corresponds to one unique treasure and one unique location.
⏱ Suggested Timing:
Total time: ~30–40 minutes
Whole-class demo (sample grid): 10 minutes
Independent or group puzzle work: 20–25 minutes
Review/discussion: 5–10 minutes
📊 Example Grid (3x3x3 Sample):
Scenario: Three animals each live in a different type of home and eat a different food.
Animals: Cat, Dog, Bird
Homes: Tree, Kennel, House
Foods: Seeds, Kibble, Fish
Sample Clues:
The dog does not live in the tree.
The cat lives in the house and does not eat kibble.
The animal that eats seeds lives in the tree.
Solution:
Cat | House | Fish
Dog | Kennel | Kibble
Bird | Tree | Seeds
Use this to model how to reason from both direct and indirect clues.
💡 Extension Ideas:
Students write a journal entry from the perspective of the first mate, explaining why and how the treasures were hidden.
Connect the logic puzzle to real-world navigation or map-making strategies.
Challenge advanced students to write their own 3x3x3 logic puzzle.
🔄 Reflection Prompts:
What strategies helped you solve this puzzle?
How did working through clues in order—or skipping around—affect your thinking?
Why might a logic puzzle like this help us think like historians or explorers?
⛵ Closing Thought:
Remind students that, like any great explorer, the ability to observe, deduce, and stay persistent often leads to the most rewarding discoveries.
🗓️ Decode & Discover: One-Week Pacing Overview
Day 1 – Launch the Mystery & Chart the Voyages
📖 Hook: Introduce the story of Captain Cook’s lost journal and the rumored hidden island.
🌍 Activity: Students begin Step 1: Chart the Voyages. They label continents, trace Cook’s 3 voyages using different colors, and apply cardinal/intercardinal directions.
💬 Discussion: What might Cook have wanted to keep hidden? Why might explorers erase maps?
Day 2 – Cipher Sleuths: Decoding the Captain’s Message
🧠 Mini-Lesson: Introduce substitution ciphers and the Caesar shift (+3).
🔐 Activity: Students work on Step 2: Decode the Captain’s Message.
🤔 Optional: Let them struggle for a bit before offering cipher help as a whole-class decode.
🌊 Reflection Prompt: What clues in the message hint at a specific voyage or place?
Day 3 – Logic in the Islands: The Puzzle Begins
🧩 Review: Recap yesterday’s message and explain that a new clue has emerged—a logic puzzle.
📊 Activity: Begin Step 3: The Island Puzzle. Review how logic grids work, then model a sample 3x3x3 together.
✍️ Student Work: Students begin solving their 4x4x4 puzzle using Xs and Os.
Day 4 – Puzzle Solving & Evidence Discussion
✅ Complete: Students finalize their logic grids and complete the answer table.
🔍 Group Discussion: Review answers together. Let students justify their conclusions.
🧭 Optional Extension: Have students write a paragraph explaining how they solved the puzzle or which clue helped the most.
Day 5 – Reflection & Optional Creative Wrap-Up
📚 Reflection: Students write journal entries as if they are part of the research team or the first mate.
🗣️ Class Share: Share journal entries or host a “Captain’s Debrief” to discuss favorite discoveries.
🧭 Closure Prompt: What did this challenge teach you about being an explorer, problem-solver, or teammate?
