What is probably happening is that as a float, 20.875 is being represented as "20.8749999999...", which, when rounded to 2 decimal places, is being represented as 20.87. (Though, theorhetically, 0.875 should be able to be represented exactly by decimal fractions, but there's still some floating point math).

A general way to round to some place can be done by the following: 

my $rounded = int ( $value / ( 10**$round ) + 0.5 ) * ( 10**$round );

[download]
where $round is the digit that you want to round to, 0 being the 1's place, 1 the tens, and -1 the tenths place. (and so forth). You'll want to do something with $round = -2 in your case here.

-----------------------------------------------------
Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
"I can see my house from here!"
It's not what you know, but knowing how to find it if you don't know that's important

In reply to Re: A simple rounding question, but can't get it! by Masem
in thread A simple rounding question, but can't get it! by DippinPete

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.