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For younger learners

  • Early Years Foundation Stage

Sliding Puzzle

Age 11 to 16
Challenge Level Yellow star
  • Game

This puzzle is an old favourite. The aim of the game is to slide the green square from its starting position, in the top right hand corner, to the bottom left hand corner in the least number of moves. You may only slide squares up, down, left or right and not diagonally.

A four by four grid, containg fifteen coloured counters and one empty space in the bottom left. The top right counter is green, the rest are purple. 

Try first on a small two by two grid and then as you become more confident, alter the size.

Can you find a strategy?



You may like to have a look at the problem Changing Places for some helpful hints.

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P is a point on the circumference of a circle radius r which rolls, without slipping, inside a circle of radius 2r. What is the locus of P?

Coke Machine

The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...

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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.

NRICH is part of the family of activities in the Millennium Mathematics Project.

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