I don't get it. It doesn't look like a logic issue, though.

issuing :%s/0\.0/0./g while editing in vi, writing and executing yields:

#!/usr/bin/perl
use strict;
use warnings;

my $base = 0.425;

while ( my $line = <DATA>){
 chomp $line;
 my ($z,$c1,$c2,$c3,$c4) = split(/,/,$line);
 print join("|",$z,$c1,$c2,$c3,$c4),"\n";
 my $total = $c1+$c2+$c3;
 print $c4  == ($total + $base) ? "True\n" : "False $c4 != ".($total+$
+base)."\n";

}
__DATA__
00501,0.000,0.425,0.025,0.875
00544,0.000,0.425,0.025,0.875
06390,0.000,0.425,0.025,0.875
[download]

with results:

00501|0.000|0.425|0.025|0.875
True
00544|0.000|0.425|0.025|0.875
True
06390|0.000|0.425|0.025|0.875
True
[download]

So making everything 10 times bigger yields expected results. Rounding error?

--Bob Niederman, http://bob-n.com