php round off value to multiples of 10

PHP Round Off values to multiples of 10

public function trimprice($currency, $x=5, $sf=2) {

$scale = pow(10,$sf);

$temp = round($currency * $scale, $sf); // get rid of small rounding errors

return number_format(round(ceil($temp / $x), $sf) * $x / $scale, $sf);

}