public function toFixed($decimals = 2) {

		if(false === ('-' . intval($decimals) == '-' . $decimals)) {
			return trigger_error(sprintf('Argument 1 passed to %s() must be of the type integer, "%s" given', __METHOD__, gettype($decimals)), E_USER_ERROR);
		}

		return $this -> convert(function($number, $decimals) {
			
			$split = explode('.', (string) $number);

			if(count($split) < 2) {
				$split[1] = str_repeat('0', $decimals);
			}

			if(strlen($split[1]) < $decimals) {
				$split[1] .= str_repeat('0', $decimals - strlen($split[1]));
			}

			return rtrim(rtrim($split[0] . '.' . substr($split[1], 0, $decimals), ','), '.');

		}, [$decimals]);
	}