1. Go to this page and download the library: Download moontoast/math library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
moontoast / math example snippets
$bn = new \Moontoast\Math\BigNumber('9,223,372,036,854,775,808');
$bn->multiply(35);
var_dump($bn->getValue());
var_dump($bn->convertToBase(16));