Counting

  • Some Secret Codes
    problem

    Some Secret Codes

    Age
    7 to 11
    Challenge level
    3 out of 3

    Can you follow the rule to decode the messages?

  • A brown snail on a green leaf.
    problem

    Slippery Snail

    Age
    7 to 16
    Challenge level
    2 out of 3

    A game for two people, who take turns to move the counters. The player to remove the last counter from the board wins.

  • How many dice?
    problem

    How Many Dice?

    Age
    11 to 14
    Challenge level
    1 out of 3

    A standard die has the numbers 1, 2 and 3 are opposite 6, 5 and 4 respectively so that opposite faces add to 7? If you make standard dice by writing 1, 2, 3, 4, 5, 6 on blank cubes you will find there are 2 and only 2 different standard dice. Can you prove this ?

  • Euromaths
    problem

    Euromaths

    Age
    11 to 14
    Challenge level
    1 out of 3

    How many ways can you write the word EUROMATHS by starting at the top left hand corner and taking the next letter by stepping one step down or one step to the right in a 5×5 array?

  • 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?

  • Colourful Tiles
    problem

    Colourful Tiles

    Age
    11 to 14
    Challenge level
    1 out of 3

    Weekly Problem 21 - 2011
    How many ways can you paint this wall with four different colours?

  • Cube Paths
    problem

    Cube Paths

    Age
    11 to 14
    Challenge level
    2 out of 3

    Given a 2 by 2 by 2 skeletal cube with one route 'down' the cube. How many routes are there from A to B?

  • Amazing Card Trick
    problem

    Amazing Card Trick

    Age
    11 to 14
    Challenge level
    2 out of 3

    How is it possible to predict the card?

  • Pairs
    problem

    Pairs

    Age
    11 to 14
    Challenge level
    3 out of 3

    Ann thought of 5 numbers and told Bob all the sums that could be made by adding the numbers in pairs. The list of sums is 6, 7, 8, 8, 9, 9, 10,10, 11, 12. Help Bob to find out which numbers Ann was thinking of.

  • Back to the Planet of Vuvv
    problem

    Back to the Planet of Vuvv

    Age
    11 to 14
    Challenge level
    3 out of 3

    There are two forms of counting on Vuvv - Zias count in base 3 and Zepts count in base 7. Can you work out in which direction the Zias and Zepts were looking, based on the information you're given?