Silly way to round two numbers to the least granular precision PHP

gistfile1.txt

<?php

function dec_points($val){
	$precision = 0;
	while($precision < 10){
		if($val == round($val, $precision)){
			break;
		}
		$precision++;
	}
	return $precision;
}

function dec_points2($val1, $val2){

	$precision = min(dec_points($val1),dec_points($val2));

	return round($val1 - $val2, $precision);
}

var_dump(dec_points2(4.5936, 4.59359782));
var_dump(dec_points2(4.5936, 4.59359782000000000000));
var_dump(dec_points2(4.59360000, 4.59359782000000000000));
var_dump(dec_points2(4.593600001, 4.59359782000000000000));
var_dump(dec_points2(4.593600001, 4.59359782));
var_dump(dec_points2(4.593600001, 4.5936));
var_dump(dec_points2(4.59360000001, 4.59359782000000000000));
var_dump(dec_points2(0.59360000001, 4.59359782000000000000));
?>