in reply to perl subtraction

61/100, 33/100 and 94/100 are all periodic numbers in binary (like 1/3 is in decimal). It would take infinite storage to represent them accurately as floats. You're noticing errors from the inability to store the numbers accurately. 
            _____
61/100 = 1.3851EB * 2**(-1)
           _____
33/100 = 1.51EB8  * 2**(-2)
           _____
94/100 = 1.E147A  * 2**(-1)

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(Using hex for the mantisa)

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Re^2: perl subtraction
by jagdish.eashwar (Novice) on Jan 10, 2010 at 09:24 UTC
    Hi,

    But 
    perl -e "print 100.61 + 100.33 - 200.94"

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    works correctly.
[reply]
[d/l]
      Sometimes the errors cancel out. Floats also do a bit of rounding for you to try to avoid problems. You need to do some of your own.
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