How do I print/round a number to a given number of decimal places?

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I faced an issue in printf which is weird If i give $unrounded="7.425" result is 7.42 and if $unrounded="8.425" the result is 8.43 Anyone here to help me...

Comment on How do I print/round a number to a given number of decimal places?

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Re^2: Answer: How do I print/round a number to a given number of decimal places? by choroba (Cardinal) on Mar 29, 2012 at 12:41 UTC
Try running this: `printf "%23.20f\n",$_+.425 for 7, 8;` [download] Maybe reading What Every Computer Scientist Should Know About Floating-Point Arithmetic can enlighten you about the reasons.	[reply] [d/l]
Re^2: Answer: How do I print/round a number to a given number of decimal places? by tangent (Parson) on Mar 29, 2012 at 17:14 UTC
I have worked around this problem by doing this before calling printf: `$number += 0.001 if $number =~ m/\.\d{2}5$/;` [download]	[reply] [d/l]