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Secondary Live Problems and Recent Solutions

Each time you visit the NRICH site there will be some activities which are 'live'. This means we are inviting students to send us solutions, and we will publish a selection of them, along with each student's name and their school, a few weeks later. If you'd like to know more about what we're looking for, read this short article.

The last day for sending solutions to these live problems is Monday 2 November.

Live problems

  • Forwards Add Backwards
    problem
    Favourite

    Forwards Add Backwards

    Age
    11 to 14
    Challenge level

    What happens when you add a three digit number to its reverse?

  • A rolled up old-fashioned treasure map.
    problem
    Favourite

    Treasure Hunt

    Age
    7 to 14
    Challenge level

    Can you find a reliable strategy for choosing coordinates that will locate the treasure in the minimum number of guesses?

  • 3D Treasure Hunt
    problem

    3D Treasure Hunt

    Age
    14 to 18
    Challenge level

    Some treasure has been hidden in a three-dimensional grid! Can you work out a strategy to find it as efficiently as possible?

Recently solved problems

  • A blue map of electronic connections between people.
    problem
    Favourite

    Connecting Averages

    Age
    11 to 16
    Challenge level

    The number in the square is the mean of the four numbers surrounding it. Can you find the missing numbers? 

  • More Less is More
    problem
    Favourite

    More Less Is More

    Age
    7 to 14
    Challenge level

    In each of these games, you will need a little bit of luck and your knowledge of place value to develop a winning strategy.

  • Dicey Operations
    game
    Favourite

    More Dicey Operations

    Age
    7 to 14
    Challenge level

    In these multiplication and division games, you'll need to think strategically to get closest to the target.

  • Unequal Averages
    problem
    Favourite

    Unequal Averages

    Age
    11 to 14
    Challenge level

    Play around with sets of five numbers and see what you can discover about different types of average...

  • Isosceles Triangles
    problem
    Favourite

    Isosceles Triangles

    Age
    11 to 14
    Challenge level

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

  • problem
    Favourite

    Simplifying Doughnut

    Age
    14 to 16
    Challenge level

    Can you match up these equivalent algebraic expressions?

  • Negative 3 to the power of negative 3.
    problem
    Favourite

    Negative Powers

    Age
    14 to 18
    Challenge level

    What does this number mean? Which order of 1, 2, 3 and 4 makes the highest value? Which makes the lowest?

  • Multiple Surprises
    problem
    Favourite

    Multiple Surprises

    Age
    11 to 16
    Challenge level

    Sequences of multiples keep cropping up...