Being resilient

  • A green frog.
    problem

    Frogs

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    How many moves does it take to swap over some red and blue frogs? Do you have a method?

  • Reflecting Squarely
    problem

    Reflecting squarely

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    In how many ways can you fit all three pieces together to make shapes with line symmetry?

  • Isosceles Triangles
    problem

    Isosceles triangles

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    Draw some isosceles triangles with an area of $9$cm$^2$ and a vertex at (20,20). If all the vertices must have whole number coordinates, how many is it possible to draw?

  • Odds and Evens
    problem

    Odds and evens

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    Are these games fair? How can you tell?

  • Substitution Cipher
    problem

    Substitution cipher

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    Find the frequency distribution for ordinary English, and use it to help you crack the code.

  • Factors and Multiples Puzzle
    problem

    Factors and multiples puzzle

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    Using your knowledge of the properties of numbers, can you fill all the squares on the board?

  • m, m and m
    problem

    M, M and M

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?

  • Elevenses
    problem

    Elevenses

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    How many pairs of numbers can you find that add up to a multiple of 11? Do you notice anything interesting about your results?

  • Multiples Sudoku
    problem

    Multiples Sudoku

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    Each clue in this Sudoku is the product of the two numbers in adjacent cells.

  • How much can we spend?
    problem

    How much can we spend?

    Age
    11 to 14
    Challenge level
    filled star empty star empty star

    A country has decided to have just two different coins. Which totals can be made? Is there a largest total that cannot be made? How do you know?