1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Confused about method to approximate a decimal number.

  1. Jun 23, 2012 #1
    1. The problem statement, all variables and given/known data
    I need to approximate the number 14.45 to nearest integer.

    2. Relevant equations

    3. The attempt at a solution
    If I remember correctly, to approximate a decimal up to say 2nd decimal place, I look at the third digit and if this is greater than or equal to 5, then I increase the 2nd decimal place, otherwise keep the 2nd decimal digit as it is. e.g., 13.672 -> 13.67, 13.549-> 13.55
    In my case what should I do? Should I first approximate to 1st decimal, then to nearest integer? Then should the answer be 14.45-> 14.5->15 Or is it operationally correct to note that .45<.5 so, 14.45->14? Which approach is correct?
  2. jcsd
  3. Jun 23, 2012 #2


    User Avatar
    Homework Helper

    This is the correct approach. If you're rounding to the nearest integer, then you just need to check what the tenths value is. The hundredths and so on won't affect the answer.
  4. Jun 23, 2012 #3


    User Avatar
    Science Advisor

    The real point is that .45 is less than 1/2 so 14.45 is close to 14 than to 15.

    The moral- don't just follow "rules" thoughtlessly- think about what they mean.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook