Prime numbers

  • Factors and Multiples Puzzle
    problem
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    Factors and Multiples Puzzle

    Age
    11 to 14
    Challenge level
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    Using your knowledge of the properties of numbers, can you fill all the squares on the board?

  • Four playing cards on top of each other. Each card shows a different ace.
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    Snappy Statements

    Age
    11 to 14
    Challenge level
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    You'll need to know your number properties to win a game of Statement Snap...

  • Factoring factorials
    problem

    Factoring Factorials

    Age
    11 to 14
    Challenge level
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    Find the highest power of 11 that will divide into 1000! exactly.

  • Powerful factorial
    problem

    Powerful Factorial

    Age
    11 to 14
    Challenge level
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    6! = 6 × 5 × 4 × 3 × 2 × 1. The highest power of 2 that divides exactly into 6! is 4 since (6!) / (2^4) = 45. What is the highest power of two that divides exactly into 100!?

  • Coins
    problem

    Coins

    Age
    11 to 14
    Challenge level
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    A man has 5 coins in his pocket. Given the clues, can you work out what the coins are?

  • HCF Expression
    problem

    HCF Expression

    Age
    11 to 14
    Challenge level
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    Find out which two distinct primes less than $7$ will give the largest highest common factor of these two expressions.

  • Different by One
    problem

    Different by One

    Age
    14 to 16
    Challenge level
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    Can you make lines of Cuisenaire rods that differ by 1?
  • Why 24?
    problem
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    Why 24?

    Age
    14 to 16
    Challenge level
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    Take any prime number greater than 3 , square it and subtract one. Working on the building blocks will help you to explain what is special about your results.

  • Factoring a million
    problem

    Factoring a Million

    Age
    14 to 16
    Challenge level
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    In how many ways can the number 1 000 000 be expressed as the product of three positive integers?

  • Public Key Cryptography
    article

    Public Key Cryptography

    An introduction to coding and decoding messages and the maths behind how to secretly share information.