php man page for gmp_mul

GMP_MUL(3)								 1								GMP_MUL(3)

gmp_mul - Multiply numbers

SYNOPSIS
       GMP gmp_mul (GMP  $a, GMP  $b)

DESCRIPTION
	Multiplies $a by $b and returns the result.

PARAMETERS
	      o $a
		-  A number that will be multiplied by $b. Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later,
		or a numeric string provided that it is possible to convert the latter to a number.

	      o $b
		- A number that will be multiplied by $a. Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and  later,
		or a numeric string provided that it is possible to convert the latter to a number.

RETURN VALUES
	A GMP number resource in PHP 5.5 and earlier, or a GMP object in PHP 5.6 and later.

EXAMPLES
       Example #1

	      gmp_mul(3) example

	      <?php
	      $mul = gmp_mul("12345678", "2000");
	      echo gmp_strval($mul) . "
";
	      ?>

	      The above example will output:

	      24691356000

PHP Documentation Group 														GMP_MUL(3)