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Multiplying in your head

Here are some tips for multiplying in your head.

  • Try 7 x 6
    Use your knowlege of times tables to recall the multiplication fact for 7 x 6 to get the answer 42.

  • 12 x 7
    Remember that 12 is 2 x 6, so 12 x 7 can also be expressed as:
    2 x 6 x 7
    (12) x 7
    Recall from your times tables that 6 x 7 = 42
    So times 42 by the remaining 2 to get the answer: 42 x 2 = 84

  • 35 x 8
    Because 8 is 2 x 2 x 2, when you work out 35 x 8, you can do it like this:
    35 x 2 x 2 x 2
    = 70 x 2 x 2
    = 140 x 2
    = 280

  • To multiply a number by 10, move the digits one place to the left, adding a zero if necessary.

    58 x 10 = 58058 multiplied by 10 = 580

  • To multiply a number by 100, move the digits two places to the left, adding zeros if necessary.

    58 x 100 = 580058 multiplied by 100

  • To multiply by numbers such as 20 or 300, multiply by the 2 or 3 first and then by the 10 or 100.

    33 x 20
    = 33 x 2 x 10
    = 66 x 10
    = 660

    22 x 300
    = 22 x 3 x 100
    = 66 x 100
    = 6600

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