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A Roman Conversion?

Age 16 to 18
Challenge Level Yellow starYellow starYellow star
  • Problem
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This challenge cipher forms part of a very difficult sequence of ciphers suitable for keen groups or individuals, maths clubs and very optional homework challenges. Don't try this in the classroom!

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Probably a Code?

Is the regularity shown in this encoded message noise or structure?

Stage 5 Cipher Challenge

Can you crack these very difficult challenge ciphers? How might you systematise the cracking of unknown ciphers?

More Secret Transmissions

In 'Secret Transmissions', Agent X could send four-digit codes error free. Can you devise an error-correcting system for codes with more than four digits?

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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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