The bcmul() function in PHP is an inbuilt function and is used to multiply two arbitrary precision numbers. This function accepts two arbitrary precision numbers as strings and returns the multiplication of the two numbers after scaling the result to a specified precision. Syntax:

string bcmul ( $num_str1, $num_str2, $scaleVal)

Parameters: This function accepts three parameters as shown in the above syntax and explained below:

• $num_str1: This parameter is of string type and represents the left operand or one of the two numbers among which we want to perform the multiplication. This parameter is mandatory.
• $num_str2: This parameter is of string type and represents the right operand or one of the two numbers among which we want to perform the multiplication. This parameter is mandatory.
• $scaleVal: This parameter is of int type and is optional. This parameter tells the number of digits that will appear after the decimal in the result of multiplication. It's default value is zero.

Return Value: This function returns the multiplication of the two numbers $num_str1 and $num_str2 as string. Examples:

Input:  $num_str1 = 3, $num_str2 = 11.222
Output: 33
Explanation: Since the parameter $scaleVal is not 
specified so no digits after decimal is appeared 
in the result after multiplication.

Input:  $num_str1 = 3, $num_str2 = 11.222, $scaleVal = 4
Output: 36.6660

Below programs illustrate the bcmul() function in PHP : Program 1:

<?php
// PHP program to illustrate bcmul() function
 
// input numbers with arbitrary precision
$num_str1 = "3";
$num_str2 = "11.222";
 
// calculates the multiplication of the two
// numbers when $scaleVal is not specified
$res = bcmul($num_str1, $num_str2);

echo $res;
 
?>

Output:

33

Program 2:

<?php
// PHP program to illustrate bcmul() function
 
// input numbers with arbitrary precision
$num_str1 = "3";
$num_str2 = "11.222";

// scale value
$scaleVal = 3;
 
// calculates the multiplication of the two
// numbers when $scaleVal is specified
$res = bcmul($num_str1, $num_str2, $scaleVal);

echo $res;
 
?>

Output:

33.666

Reference: http://php.net/manual/en/function.bcmul.php