Exploring and noticing

  • One to Eight
    problem

    One to eight

    Age
    11 to 14
    Challenge level
    filled star filled star filled star
    Complete the following expressions so that each one gives a four digit number as the product of two two digit numbers and uses the digits 1 to 8 once and only once.
  • What's Possible?
    problem

    What's possible?

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?

  • problem

    Cut it out

    Age
    7 to 11
    Challenge level
    filled star filled star filled star

    Can you dissect an equilateral triangle into 6 smaller ones? What number of smaller equilateral triangles is it NOT possible to dissect a larger equilateral triangle into?

  • Fair Shares?
    problem

    Fair shares?

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    A mother wants to share some money by giving each child in turn a lump sum plus a fraction of the remainder. How can she do this to share the money out equally?

  • Napkin
    problem

    Napkin

    Age
    14 to 16
    Challenge level
    filled star filled star filled star

    A napkin is folded so that a corner coincides with the midpoint of an opposite edge. Investigate the three triangles formed.

  • Of all the areas
    problem

    Of all the areas

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    Can you find a general rule for finding the areas of equilateral triangles drawn on an isometric grid?

  • Sitting Pretty
    problem

    Sitting pretty

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    A circle of radius r touches two sides of a right angled triangle, sides x and y, and has its centre on the hypotenuse. Can you prove the formula linking x, y and r?

  • Plus Minus
    problem

    Plus minus

    Age
    14 to 16
    Challenge level
    filled star filled star empty star

    Can you explain the surprising results Jo found when she calculated the difference between square numbers?

  • Alphabet Soup
    problem

    Alphabet soup

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    This challenge is to make up YOUR OWN alphanumeric. Each letter represents a digit and where the same letter appears more than once it must represent the same digit each time.
  • How old am I?
    problem

    How old am I?

    Age
    14 to 16
    Challenge level
    filled star empty star empty star

    In 15 years' time my age will be the square of my age 15 years ago. Can you work out my age, and when I had other special birthdays?