如何在PHP中将crores中的金额转换为十进制值？

<?PHP
function count_digit($number) {
  return strlen($number);
}

function divider($number_of_digits) {
    $tens="1";

  if($number_of_digits>8)
    return 10000000;

  while(($number_of_digits-1)>0)
  {
    $tens.="0";
    $number_of_digits--;
  }
  return $tens;
}
//function call
$num = "789";
$ext="";//thousand,lac,crore
$number_of_digits = count_digit($num); //this is call :)
    if($number_of_digits>3)
{
    if($number_of_digits%2!=0)
        $divider=divider($number_of_digits-1);
    else
        $divider=divider($number_of_digits);
}
else
    $divider=1;

$fraction=$num/$divider;
$fraction=number_format($fraction,2);
if($number_of_digits==4 ||$number_of_digits==5)
    $ext="k";
if($number_of_digits==6 ||$number_of_digits==7)
    $ext="Lac";
if($number_of_digits==8 ||$number_of_digits==9)
    $ext="Cr";
echo $fraction." ".$ext;
?>

>计算number_of_digit
>取(number_of_digit-1)数十位数值
>除以它.
>从数字位数中查找值的扩展名.
>输出将是

如果任何测试用例失败.请告诉我.我会纠正