Rational and irrational numbers

  • Continued Fractions II
    article

    Continued fractions II

    In this article we show that every whole number can be written as a continued fraction of the form k/(1+k/(1+k/...)).

  • All is Number
    article

    All is number

    Read all about Pythagoras' mathematical discoveries in this article written for students.

  • The Dangerous Ratio
    article

    The dangerous ratio

    This article for pupils and teachers looks at a number that even the great mathematician, Pythagoras, found terrifying.
  • What Are Numbers?
    article

    What are numbers?

    Ranging from kindergarten mathematics to the fringe of research this informal article paints the big picture of number in a non technical way suitable for primary teachers and older students.
  • Proof Sorter - The Square Root of 2 is Irrational
    interactivity

    Proof sorter - the square root of 2 is irrational

    Age
    16 to 18
    Challenge level
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    Try this interactivity to familiarise yourself with the proof that the square root of 2 is irrational. Sort the steps of the proof into the correct order.
  • Good Approximations
    problem

    Good approximations

    Age
    16 to 18
    Challenge level
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    Solve quadratic equations and use continued fractions to find rational approximations to irrational numbers.
  • Be reasonable
    problem

    Be reasonable

    Age
    16 to 18
    Challenge level
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    Prove that sqrt2, sqrt3 and sqrt5 cannot be terms of ANY arithmetic progression.