Project Euler puzzle 17, How many letters would be needed to write all the numbers in words from 1 to 1000?

How many letters would be needed to write all the numbers in words from 1 to 1000?

WARNING: The code must be American because of the spelling, it is Forty not Fourty etc.

I’d like to credit this site for the numbers to words script, I changes the spellings though.

function convert_number($number)
{
    if (($number < 0) || ($number > 999999999))
    {
    throw new Exception("Number is out of range");
    } 

    $Gn = floor($number / 1000000);  /* Millions (giga) */
    $number -= $Gn * 1000000;
    $kn = floor($number / 1000);     /* Thousands (kilo) */
    $number -= $kn * 1000;
    $Hn = floor($number / 100);      /* Hundreds (hecto) */
    $number -= $Hn * 100;
    $Dn = floor($number / 10);       /* Tens (deca) */
    $n = $number % 10;               /* Ones */ 

    $res = ""; 

    if ($Gn)
    {
        $res .= convert_number($Gn) . " Million";
    } 

    if ($kn)
    {
        $res .= (empty($res) ? "" : " ") .
            convert_number($kn) . " Thousand";
    } 

    if ($Hn)
    {
        $res .= (empty($res) ? "" : " ") .
            convert_number($Hn) . " Hundred";
    } 

    $ones = array("", "One", "Two", "Three", "Four", "Five", "Six",
        "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen",
        "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen",
        "Nineteen");
    $tens = array("", "", "Twenty", "Thirty", "Forty", "Fifty", "Sixty",
        "Seventy", "Eighty", "Ninety"); 

    if ($Dn || $n)
    {
        if (!empty($res))
        {
            $res .= " and ";
        } 

        if ($Dn < 2)
        {
            $res .= $ones[$Dn * 10 + $n];
        }
        else
        {
            $res .= $tens[$Dn]; 

            if ($n)
            {
                $res .= "-" . $ones[$n];
            }
        }
    } 

    if (empty($res))
    {
        $res = "zero";
    } 

    return $res;
} 

$i = 1;
$total = '';
while($i < 1001){
	$total = $total . convert_number($i);
	$i++;
}
// take out spaces and hyphens
$total = str_replace(' ', '', $total);
$total = str_replace('-', '', $total);
#echo $total;
echo strlen($total);

Project Euler puzzle 16, What is the sum of the digits of the number 21000?

What is the sum of the digits of the number 2¹⁰⁰⁰?

$var = 2;
$i = 0;
while($i < 999){
    $var = $var * 2;
    $i++;
}
$result = number_format($var);
$result = str_replace(',', '',$result);
$array = str_split($result);
$final = 0;
foreach($array as $char){
    $final = $final + $char;
}
echo $final;