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Dash as multiplication sign in older texts

  1. Oct 9, 2012 #1


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    Sometimes I have seen a dash (-) being used as multiplication sign, usually in connection with units. Does anybody know where this strange custom has it's origin?
  2. jcsd
  3. Oct 9, 2012 #2


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    It's a hyphen: it's taking the two words and amalgamating them into a single hyphenated word.
  4. Oct 10, 2012 #3


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    Nevertheless I find units like "mg m-3-years" very confusing.
  5. Oct 10, 2012 #4
    There is sense in that statement.

    Consider some poor Physics Forum member typing here

    mg / m3 years


    mg / m3 /years


    (mg / m3) years

    you try typing this and then have a doubt as to whether the years should be on the top or the bottom. Or whether others will interpret it as you have.

    The hyphen is a good way to make certain.

    Another way is simply to coin a new unit.


    Newton-metres = joules

    go well
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