Mission: The Sequence Strategist — Level 7
Akuuu finds a mysterious number machine in her grandfather’s attic. It shows a sequence of numbers that keeps growing:
2, 5, 11, 23, 47, ❓
Her brother says: “Just add 3 each time — the next number is 50!”
Her sister says: “No, look closer — each number depends on the one before it in a trickier way.”
👉 Who is closer to the truth? What is the real rule?
Think: Check the gaps between numbers. Are they the same? Or is something else happening?
✏️ Write your guess for the next number and the rule:
- 📈 A number series follows a hidden rule that connects each term to the next
- 🔍 To find the rule, check: difference (add/subtract), ratio (multiply/divide), or mixed operations
- ✅ Always test your rule on at least 3 terms before trusting it
In the series 2, 5, 11, 23, 47:
5 − 2 = 3
11 − 5 = 6
👉 What are the next two gaps? What pattern do you see in the gaps themselves?
Akuuu finds another machine with a different series:
3, 6, 12, 24, 48, ❓
👉 Is this the same type of rule as the first machine? How is it different?
👉 Compare the two machines. When do gaps help? When do ratios help?
1, 4, 9, 16, 25, ❓, ❓
👉 What is the rule? Find the next two numbers and explain how you know.
A child looks at 2, 4, 8, 16 and says: “The rule is add 2, then add 4, then add 8… so the gaps double!”
👉 Is their rule wrong? Can you find a simpler rule that also works?
A series has a hole: 5, 11, ❓, 23, 29
👉 What is the missing number? How did you find it without knowing the rule first?
🧠 Part A — Transfer
Before solving, look at this series:
1, 1, 2, 3, 5, 8, 13, ❓
👉 Do NOT calculate yet. Just predict: Will the gaps grow? Shrink? Stay the same? Why?
Now solve it:
👉 What is the rule? Name this famous series and find the next two numbers.
Think: Was your prediction correct? In this series, each number is built from the two before it — not just one. How does that change the growth?
🧠 Part B — Thinking Pause
- I planned my strategy before calculating
- I tested my rule on multiple examples
- I found a simpler rule when one was too complicated
⭐ Mission Reflection
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