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Have You Got It?

Can you explain the strategy for winning this game with any target?

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Is There a Theorem?

Draw a square. A second square of the same size slides around the first always maintaining contact and keeping the same orientation. How far does the dot travel?

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Card Trick 2

Can you explain how this card trick works?

Hidden Rectangles

Age 11 to 14 Challenge Level:

Picture of rectangles

Rectangles are considered different if they vary in size or have different locations.

How many different rectangles can be drawn on a chessboard?

How many of the rectangles are squares?

What happens on an n by n board?


The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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NRICH is part of the family of activities in the Millennium Mathematics Project.