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Homework Help: Unit conversions and significant digits

  1. Mar 12, 2008 #1
    Let's us say I was given 100.0 kg of something.
    That number has 4 significant digits.
    Now let's say I wanted to convert that to grams.
    It would be 100,000g.

    but even if I write that as 100,000. it would be 6 significant digits.
    Is my only option for this case to write it in scientific notation?

    SO it would be 1.000*10^5 g
  2. jcsd
  3. Mar 12, 2008 #2
    you can put a line above the last zero that you want to be significant
  4. Mar 12, 2008 #3
    So just mark the second 0 from the right for 10,000 to make a mental note that it only has 4 significant digits?

    But my methodology for using scientific notation is correct too right?
    Could you please explain a bit more about what you meant by that dranseth.
  5. Mar 12, 2008 #4


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    In your calculations you can write out the 100,000 but as the number gets bigger it is best to use scientific notation so you have less digits to write out.
    so 100,000 would be 1.0*10^5 g
  6. Mar 12, 2008 #5
    I'll give you an example


    see where the 0 is underlined? Flip it so that line is on top of the 0 instead of on the bottom
  7. Mar 13, 2008 #6
    Ok when you did that you are left with 2 significant digits.
    The original was 4.
    Is that ok to do it that way?
  8. Mar 13, 2008 #7


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    Well my deal with scientific notation is to reduce the number of decimal places.( Not sure if I am correct with what I am about to say)

    But 100,000=1*10^5
    I usually regard the trailing zero's as placeholders so that if I have to write it in scientific notation I would write 1.0*10^5 to 2sf. Or else I would have to write 1.000 *10^5 which in my eyes would be pointless to do (write 1.000 that is)
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