Description:
------------
If you assign 2.8 on PHP you get:
2.79999999999999982236431605997495353221893310546875

if you do:
  $n = 2.8;
  $n = $n+$n+$n+$n+$n+$n+$n+$n+$n+$n;
and compare:
  $n == 28
will be false.

2.8 is 2.8.
Nothing more or less.





Reproduce code:
---------------
$n = 2.8;
echo serialize($n).'<br />';

$n = $n+$n+$n+$n+$n+$n+$n+$n+$n+$n;

if ($n == 28) {
  echo 'right';
} else {
  echo 'wrong';
}

Expected result:
----------------
d:2.8;
right

Actual result:
--------------
d:2.79999999999999982236431605997495353221893310546875;
wrong