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Number and algebra

  • The Number System and Place Value
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Working mathematically

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Advanced mathematics

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For younger learners

  • Early Years Foundation Stage

Sequences and Series

Circles Ad Infinitum

Age 16 to 18
Challenge Level Yellow starYellow star

A circle is inscribed in an equilateral triangle. Smaller circles touch it and the sides of the triangle, the process continuing indefinitely. What is the sum of the areas of all the circles?

Direct Logic

Age 16 to 18
Challenge Level Yellow star

Can you work through these direct proofs, using our interactive proof sorters?

Speedy Summations

Age 16 to 18
Challenge Level Yellow star

Watch the video to see how to add together an arithmetic sequence of numbers efficiently.

Prime Aps

Age 16 to 18
ShortChallenge Level Yellow star

What can you deduce about prime numbers in arithmetic progression?

Mad Robot

Age 16 to 18
ShortChallenge Level Yellow star

Can you work out what happens when this mad robot sets off?

AP Train

Age 16 to 18
ShortChallenge Level Yellow star

An arithmetic progression is shifted and shortened, but its sum remains the same...

Medicine Half Life

Age 14 to 18
Challenge Level Yellow star

A short challenge concerning the decay of medicines in the body.

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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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