Networks/graph theory

  • Euler's Formula
    article

    Euler's formula

    Some simple ideas about graph theory with a discussion of a proof of Euler's formula relating the numbers of vertces, edges and faces of a graph.
  • Tangles
    article

    Tangles

    A personal investigation of Conway's Rational Tangles. What were the interesting questions that needed to be asked, and where did they lead?
  • Symmetric Tangles
    article

    Symmetric tangles

    The tangles created by the twists and turns of the Conway rope trick are surprisingly symmetrical. Here's why!
  • The Four Colour Theorem
    article

    The four colour theorem

    The Four Colour Conjecture was first stated just over 150 years ago, and finally proved conclusively in 1976. It is an outstanding example of how old ideas can be combined with new discoveries. prove a mathematical theorem.
  • Placeholder: several colourful numbers
    article

    Neural nets

    Find out some of the mathematics behind neural networks.
  • Plum Tree
    problem

    Plum tree

    Age
    14 to 18
    Challenge level
    filled star empty star empty star
    Label this plum tree graph to make it totally magic!
  • Knight Defeated
    problem

    Knight defeated

    Age
    14 to 16
    Challenge level
    filled star empty star empty star
    The knight's move on a chess board is 2 steps in one direction and one step in the other direction. Prove that a knight cannot visit every square on the board once and only (a tour) on a 2 by n board for any value of n. How many ways can a knight do this on a 3 by 4 board?
  • W Mates
    problem

    W mates

    Age
    16 to 18
    Challenge level
    filled star empty star empty star
    Show there are exactly 12 magic labellings of the Magic W using the numbers 1 to 9. Prove that for every labelling with a magic total T there is a corresponding labelling with a magic total 30-T.