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Mind Reading

Age 11 to 14
Challenge Level Yellow star
  • Problem
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Think of a number, Add one, Double it, Take away 3, Add the number you first thought of, Add 7, divide by 3, take away the number you first thought of, You should now be left with 2. How do I know?

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Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

Where Can We Visit?

Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?

Prime Magic

Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?

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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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