Read the PHP manual about "variable variables" (no typo, it is really called "variable variables")
$tes=1;
$mynewvarname="test".$tes;
$$mynewvarname="Works";
echo $test1;
But be carefull about where you implement this,
expecially if you are just adding numbers to a string name, it might be better to use an array:
$myarray=array();
$myarray[1]="Works";
$myarray[2]="Feeb";
$tes=1;
echo $myarray[$tes];