Factors and multiples

  • Zios and Zepts
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    Zias and Zepts

    Age
    7 to 11
    Challenge level
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    On the planet Vuv there are two sorts of creatures. The Zias have 3 legs and the Zepts have 7 legs. The great planetary explorer Nico counted 52 legs. How many Zias and how many Zepts were there?

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    Abundant Numbers

    Age
    7 to 11
    Challenge level
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    48 is called an abundant number because it is less than the sum of its factors (without itself). Can you find some more abundant numbers?

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    Flashing Lights

    Age
    7 to 11
    Challenge level
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    Norrie sees two lights flash at the same time, then one of them flashes every 4th second, and the other flashes every 5th second. How many times do they flash together during a whole minute?

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    The Moons of Vuvv

    Age
    7 to 11
    Challenge level
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    The planet of Vuvv has seven moons. Can you work out how long it is between each super-eclipse?

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    Multiplication Squares

    Age
    7 to 11
    Challenge level
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    Can you work out the arrangement of the digits in the square so that the given products are correct? The numbers 1 - 9 may be used once and once only.

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    Which Is Quicker?

    Age
    7 to 11
    Challenge level
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    Which is quicker, counting up to 30 in ones or counting up to 300 in tens? Why?

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    A Mixed-Up Clock

    Age
    7 to 11
    Challenge level
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    There is a clock-face where the numbers have become all mixed up. Can you find out where all the numbers have got to from these ten statements?

  • Music to my Ears
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    Music to My Ears

    Age
    7 to 11
    Challenge level
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    Can you predict when you'll be clapping and when you'll be clicking if you start this rhythm? How about when a friend begins a new rhythm at the same time?

  • What's in the Box?
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    What's in the Box?

    Age
    7 to 11
    Challenge level
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    This big box multiplies anything that goes inside it by the same number. If you know the numbers that come out, what multiplication might be going on in the box?