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# Hundred Square

This problem is also available in French: Grille de 100

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### Exploring Wild & Wonderful Number Patterns

### Magazines

### Pebbles

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Age 5 to 11

Challenge Level

A hundred square has been printed on both sides of a piece of paper. One square is directly behind the other.

What is on the back of $100$? $58$? $23$? $19$?

Can you see a pattern?

Click here for a poster of this problem.

This problem is also available in French: Grille de 100

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

Let's suppose that you are going to have a magazine which has 16 pages of A5 size. Can you find some different ways to make these pages? Investigate the pattern for each if you number the pages.

Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?