<?php

if(isset($_POST['calcola']))
{
$valore=$_POST['numero'];
$percentuale=1+ ($_POST['percentuale'] / 100) ;
$tot= $valore*$percentuale;
$tot=number_format($tot, 2, ',' , '.');

}
?>



<html>
<head>
<title> percentuale </title>
</head>
<body>
<form method="post" action="">
numero: <input type = "text" name="numero">
percentuale( non esprimere il simbolo % ) <input type="text" name="percentuale">
<input type = "submit" value="calcola" name="calcola">
</form>

<input type = "text" name="tot" value="<?php if($tot)echo $tot;?>" onlyread=onlyread />
</body>
</html>