Creating a Loop to Add Each Number?

Like what they use for numerology

[aeae]

I have a nine digit number, lets say its "496849305".

How can I add up each number till its 1 digit long?

Ie:

4+9+6+8+4+9+3+0+5=48
4+8=12
1+2=3

496849305 => 3

[RonPK]

* use str_split() to break the string into an array
* use array_sum() to calculate the sum
* have the loop continue until strlen == 1

while (strlen($string) > 1) { 
 $string = str_split($string); 
 $string = array_sum($string); 
} 

[aeae]

Thank you so much,

That elegant script worked perfectly!