How to change the value of the field before displaying? Rate = Rate*10?????
...
private $db = array(
'Rate' => 'Text'
);

...

function getCMSFields(){
$fields = parent::getCMSFields();

$Rate = new TextField('Rate', 'Процент, %','00','2');
$fields->addFieldToTab('Root.Main', $Rate, 'DateFormat');

$myValue = $this->Rate * 10;
$Rate = new TextField('Rate', 'Процент, %', $myValue );

cheers

Hello!
It is work but does not.
I need to change the value after reading from database.

private static $db = array(
'Rate' => 'Text' <----This value
);