Odd and even numbers

  • Odds and Evens
    problem
    Favourite

    Odds and Evens

    Age
    11 to 14
    Challenge level

    Are these games fair? How can you tell?

  • Odds, Evens and More Evens
    problem
    Favourite

    Odds, Evens and More Evens

    Age
    11 to 14
    Challenge level

    Alison, Bernard and Charlie have been exploring sequences of odd and even numbers, which raise some intriguing questions...

  • Magic Letters
    problem
    Favourite

    Magic Letters

    Age
    11 to 14
    Challenge level

    Charlie has made a Magic V. Can you use his example to make some more? And how about Magic Ls, Ns and Ws?

  • Score
    problem

    Score

    Age
    11 to 14
    Challenge level
    There are exactly 3 ways to add 4 odd numbers to get 10. Find all the ways of adding 8 odd numbers to get 20. To be sure of getting all the solutions you will need to be systematic. What about a total of 15 with 6 odd numbers?
  • Next-door Numbers
    problem

    Next-Door Numbers

    Age
    5 to 7
    Challenge level

    Florence, Ethan and Alma have each added together two 'next-door' numbers. What is the same about their answers?

  • The Set of Numbers
    problem

    The Set of Numbers

    Age
    5 to 7
    Challenge level
    Can you place the numbers from 1 to 10 in the grid?
  • Sorting Numbers
    problem

    Sorting Numbers

    Age
    5 to 7
    Challenge level
    Can you sort numbers into sets? Can you give each set a name?
  • What number?
    problem

    What Number?

    Age
    5 to 7
    Challenge level
    I am less than 25. My ones digit is twice my tens digit. My digits add up to an even number.
  • Numbers as Shapes
    problem

    Numbers as Shapes

    Age
    5 to 7
    Challenge level

    Use cubes to continue making the numbers from 7 to 20. Are they sticks, rectangles or squares?

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