PHP rounding error

Question

I\'m using PHP 5.2.13 on my linux server. I\'m getting weird error when rounding numbers. This is my test case:

Answer 1

The code in the answer of Shabbyrobe does not handle negative numbers. This is a working improvement of the code, which handles negative numbers as well as the default scale:

function bcround($number, $scale = null) {
    if (is_null($scale)) {
        $scale = bcscale();
    }
    $fix = ($number < 0) ? '-' : '';
    $fix .= '0.' . str_repeat('0', $scale) . '5';
    $number = bcadd($number, $fix, $scale + 1);
    return bcdiv($number, "1.0", $scale);
}