Square numbers

  • Fitted
    problem
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    Fitted

    Age
    7 to 11
    Challenge level
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    Nine squares with side lengths 1, 4, 7, 8, 9, 10, 14, 15, and 18 cm can be fitted together to form a rectangle. What are the dimensions of the rectangle?

  • Square subtraction
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    Square Subtraction

    Age
    7 to 11
    Challenge level
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    Look at what happens when you take a number, square it and subtract your answer. What kind of number do you get? Can you prove it?

  • Picturing Square Numbers
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    Picturing Square Numbers

    Age
    11 to 14
    Challenge level
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    Square numbers can be represented as the sum of consecutive odd numbers. What is the sum of 1 + 3 + ..... + 149 + 151 + 153?

  • Sticky Numbers
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    Sticky Numbers

    Age
    11 to 14
    Challenge level
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    Can you arrange the numbers 1 to 17 in a row so that each adjacent pair adds up to a square number?

  • Factors and Multiples Puzzle
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    Factors and Multiples Puzzle

    Age
    11 to 14
    Challenge level
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    Using your knowledge of the properties of numbers, can you fill all the squares on the board?

  • Four Coloured Lights
    problem

    Four Coloured Lights

    Age
    11 to 14
    Challenge level
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    Imagine a machine with four coloured lights which respond to different rules. Can you find the smallest possible number which will make all four colours light up?
  • Smith and Jones
    problem

    Smith and Jones

    Age
    14 to 16
    Challenge level
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    Mr Smith and Mr Jones are two maths teachers. By asking questions, the answers to which may be right or wrong, Mr Jones is able to find the number of the house Mr Smith lives in... Or not!

  • Generating Triples
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    Generating Triples

    Age
    14 to 16
    Challenge level
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    Sets of integers like 3, 4, 5 are called Pythagorean Triples, because they could be the lengths of the sides of a right-angled triangle. Can you find any more?

  • Odd Differences
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    Odd Differences

    Age
    14 to 16
    Challenge level
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    The diagram illustrates the formula: 1 + 3 + 5 + ... + (2n - 1) = n² Use the diagram to show that any odd number is the difference of two squares.

  • Summing squares
    problem

    Summing Squares

    Age
    14 to 16
    Challenge level
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    Discover a way to sum square numbers by building cuboids from small cubes. Can you picture how the sequence will grow?