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Secondary Cipher Challenge Part 1

Age 11 to 16
Challenge Level Yellow starYellow star
  • Problem
  • Getting Started
  • Teachers' Resources

Why do this problem?

Together with Substitution Transposed, this problem provides a challenging follow-up for students who have worked on Substitution Cipher and Transposition Cipher.

 

Possible approach

As this problem is quite lengthy, with some quite challenging codes towards the end, it could be offered as an extension for those students who have sailed through the easier codebreaking problems.

One possible approach for the whole class is to divide the group up into teams so that each team can tackle the challenges collaboratively, in competition with the others.

If a computer room is available, introduce students to the Cipher Challenge Toolkit and give them plenty of time to explore it and learn how to use the tools.

 

Possible extension

The Stage 5 Cipher Challenge offers a set of seven very difficult linked ciphers to crack.

Possible support

The challenges have been carefully chosen to get progressively more difficult; the first three should be accessible to anyone who has completed Substitution Cipher.

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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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