Working systematically

  • Small tomato seedlings in pink pots.
    problem

    Mini Kakuro

    Age
    11 to 14
    Challenge level
    1 out of 3

    The sum of each column and row in this grid give the totals as shown. What number goes in the starred square?

  • The ace, two and three of hearts.
    problem

    Ace, Two, Three...

    Age
    11 to 14
    Challenge level
    1 out of 3

    Can you picture how to order the cards to reproduce Charlie's card trick for yourself?

  • 9 Weights
    problem

    9 Weights

    Age
    11 to 14
    Challenge level
    1 out of 3

    You have been given nine weights, one of which is slightly heavier than the rest. Can you work out which weight is heavier in just two weighings of the balance?

  • Small tomato seedlings in pink pots.
    problem

    Loose Change

    Age
    11 to 14
    Challenge level
    1 out of 3

    In how many ways can you give change for a ten pence piece?

  • Multiples Sudoku
    problem

    Multiples Sudoku

    Age
    11 to 14
    Challenge level
    1 out of 3

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

  • Island Hopping
    problem

    Island Hopping

    Age
    11 to 14
    Challenge level
    1 out of 3

    What is the smallest number of ferry trips that Neda needs to take to visit all four islands and return to the mainland?

  • Small pepper seedlings in turquoise pots.
    problem

    Grid Without Lines

    Age
    11 to 14
    Challenge level
    1 out of 3

    Can you remove the least number of points from this diagram, so no three of the remaining points are in a straight line?

  • Kept Apart
    problem

    Kept Apart

    Age
    11 to 14
    Challenge level
    1 out of 3

    The squares of this grid contain one of the letters P, Q, R and S. Can you complete this square so that touching squares do not contain the same letter? How many possibilities are there?

  • Small pepper seedlings in orange pots.
    problem

    Fruit Line-Up

    Age
    11 to 14
    Challenge level
    1 out of 3

    This grocer wants to arrange his fruit in a particular order, can you help him?