php decimal round mode is not workig code example

Example: php 2 decimal places without rounding

<?php 
function cutAfterDot($number, $afterDot = 2){
$a = $number * pow(10, $afterDot);
$b = floor($a);
$c = pow(10, $afterDot);
echo "a $a, b $b, c $c<br/>";
return $b/$c ;
}
echo cutAfterDot(2.05,2);

/*
output =   a 205, b 204, c 100 
2.04
*/

?>