mash

<?php
// anyideas why I get error 
//Parse error: syntax error, unexpected '=' in /home/ircdev/public_html/calc.php(4) : eval()'d code on line 1
// on eval() ???

$formula = "(20+3)/2+1";
echo (20+3)/2+1;
eval("$return = $formula;");
echo $return;

?>