I dunno what to tell you, except you're dealing with floats... deal with ints instead ... (I have no insight, only code, well a little insight - perl has internal ways of distinguishing numbers from strings .... (s)printf are c functions, do stuff similar to (un)pack in fsking with the numbers ... that kinda it, vague ain't it ) 
#!/usr/bin/perl

my $one = 7 + (2 - (0.5 * 9));

my $two = 7 + (2 - (0.5 * 9));

my $thr = 7 + (5 - (0.5 * 9));

for($one,$two,$thr) {

    printf "no_ROUND(%s) yes_ROUND(%d)
            foy_FLOAT(%f) foy_ROUND(%.0f)\n\n",
            $_,$_,$_,$_;

=head2 UPDATE: uncomment this to add to the mistery

    print "pack i ".unpack('i*', pack('i*', $_))."\n";
    print "pack l ".unpack('l*', pack('l*', $_))."\n";
    print "pack f ".unpack('f*', pack('f*', $_))."\n";
    print "pack d ".unpack('d*', pack('d*', $_))."\n";

=cut and don't forget cut#

}

__END__

=pod

C:\>perl round.txt
no_ROUND(4.5) yes_ROUND(4)
            foy_FLOAT(4.500000) foy_ROUND(5)

no_ROUND(4.5) yes_ROUND(4)
            foy_FLOAT(4.500000) foy_ROUND(5)

no_ROUND(7.5) yes_ROUND(7)
            foy_FLOAT(7.500000) foy_ROUND(8)


=head1 that is an interesting way to get an int

            %%   a percent sign
            %c   a character with the given number
            %s   a string
            %d   a signed integer, in decimal
            %u   an unsigned integer, in decimal
            %o   an unsigned integer, in octal
            %x   an unsigned integer, in hexadecimal
            %e   a floating-point number, in scientific notation
            %f   a floating-point number, in fixed decimal notation
            %g   a floating-point number, in %e or %f notation

=cut

[download]
update: guha brings up a good point, ints/floats will still vary from system 2 system

 
______crazyinsomniac_____________________________
Of all the things I've lost, I miss my mind the most.
perl -e "$q=$_;map({chr unpack qq;H*;,$_}split(q;;,q*H*));print;$q/$q;"

In reply to (crazyinsomniac) Re: Rounding With sprintf anomaly? by crazyinsomniac
in thread Rounding With sprintf anomaly? by oakbox

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