Factors, Multiples & Primes

  • Dozens
    problem
    Favourite

    Dozens

    Age
    7 to 14
    Challenge level
    1 out of 3

    Can you select the missing digit(s) to find the largest multiple?

  • A First Product Sudoku
    problem
    Favourite

    A First Product Sudoku

    Age
    7 to 14
    Challenge level
    1 out of 3

    Given the products of adjacent cells, can you complete this Sudoku?

  • Factors and Multiples Game
    game
    Favourite

    Factors and Multiples Game

    Age
    7 to 16
    Challenge level
    1 out of 3

    A game in which players take it in turns to choose a number. Can you block your opponent?

  • Xavi's T-shirt
    problem
    Favourite

    Xavi's T-Shirt

    Age
    7 to 16
    Challenge level
    1 out of 3

    How much can you read into a T-shirt?

  • An American flag waving in the wind.
    problem
    Favourite

    American Billions

    Age
    11 to 14
    Challenge level
    1 out of 3

    Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...

  • How much can we spend?
    problem
    Favourite

    How Much Can We Spend?

    Age
    11 to 14
    Challenge level
    1 out of 3

    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?

  • Diminishing Returns
    problem
    Favourite

    Diminishing Returns

    Age
    11 to 14
    Challenge level
    1 out of 3

    How much of the square is coloured blue? How will the pattern continue?

  • Number Families
    problem
    Favourite

    Number Families

    Age
    11 to 14
    Challenge level
    1 out of 3

    How many different number families can you find?

  • Sieve of Eratosthenes
    problem
    Favourite

    Sieve of Eratosthenes

    Age
    11 to 14
    Challenge level
    1 out of 3

    Follow this recipe for sieving numbers and see what interesting patterns emerge.

  • Gabriel's Problem
    problem
    Favourite

    Gabriel's Problem

    Age
    11 to 14
    Challenge level
    1 out of 3

    Gabriel multiplied together some numbers and then erased them. Can you figure out where each number was?