Working with large numbers in PHP

Question

To use modular exponentiation as you would require when using the Fermat Primality Test with large numbers (100,000+), it calls for some very large calculations.

Whe

Answer 1

use this

 $num1 = "123456789012345678901234567890";
 $num2 = "9876543210";
 $r    = mysql_query("Select @sum:=$num1 + $num2");
 $sumR = mysql_fetch_row($r);
 $sum  = $sumR[0];