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For younger learners

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Adding and Multiplying

Age 11 to 14
ShortChallenge Level Yellow star
Secondary curriculum
  • Problem
  • Solutions

Amy was asked to multiply a number by 8 and then add 5.
Instead, she added 8 to the number, then multiplied the result by 5.
This gave her 2015.

What would the answer have been if Amy had followed the instructions correctly?




This problem is adapted from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.

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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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