What are common pitfalls when dealing with numeric data types in PHP, especially in multiplication operations?

One common pitfall when dealing with numeric data types in PHP, especially in multiplication operations, is the risk of integer overflow. PHP's default integer type is signed, which means it has a limited range before it overflows and potentially produces unexpected results. To avoid this issue, you can use the `bcmath` extension in PHP, which provides arbitrary precision mathematics and can handle large numbers without overflowing.

// Using the bcmath extension to perform multiplication with arbitrary precision

$num1 = "12345678901234567890";
$num2 = "98765432109876543210";

$result = bcmul($num1, $num2);

echo $result;