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KeyStage 2 Upper

Puzzle using place value of numbers in the millions (Investigation)


Here are a list of national parks from around the world, and the number of acres they cover.  

National Park Size (in Acres)


4 716 726

Gates of the Arctic

7 523 888


3 716 000

Kobuk Valley

1 750 421

Lake Clark

2 636 839

Glacier bay

3 225 284






The Puzzle

From the following clues, can you identify the park (or parks) with the area described?

  • The digit in the ten thousands place is less than the digit in the hundred thousands place.
  • The thousands place digit is larger than the digit in the millions place.
  • The digit in the ones place is at least twice as large as the digit in the tens place.


  1. Write another clue that would produce only one park as the answer.
  2. Choose a park from the table.  Write a set of clues to identify your park.  Describe your clues to a partner and see if they can guess the park you chose.  


Problem Adapted from an example in Open Ended Questions for Mathematics published by Appalachian Rural Systemic Initiative in 2000. 

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