Untitled

<html>
    <head> <title>Calc</title> </head>
    <body> <form action="calc.php" method="post"> Digite Aqui: <input type="text" name="num" /><br /> <br /> <br /> <input type="submit" value="submeter" /> <br /> <br /> </form>
    </body>
</html>
<?php
 $lol = explode("x", $_POST['num']);
echo "O resultado foi: ".$lol[0]*$lol[1];
?>