Hello!
Please consider the following code since BcMath\Number was added in PHP 8.4:
use BcMath\Number;
$a = new Number('1.005');
$b = new Number('2.567');
$result = $a * $b; // $result will be typed as float|int, instead of Number.
echo $result->round(2); // round() will be unrecognized as a function because $result isn't recognized as Number.
$a = new Number('1.005');
$result = $a * '2.21'; // $result should also be a Number here.