For arbitrary precision mathematics PHP offers the
Binary Calculator which supports numbers of any size
and precision, represented as strings.
Since PHP 4.0.4, libbcmath is bundled with PHP.
You don't need any external libraries for this
extension.
In PHP 4, these functions are only available if
PHP was configured with --enable-bcmath. In PHP 3, these
functions are only available if
PHP was NOT configured with
--disable-bcmath.
The windows version of PHP
has built in support for this extension. You do not
need to load any additional extension in order to use
these functions.