Your first point of action when an echo does something unexpected is to use var_dump. You'll probably find that, if you're trying to echo $countR, it will say that the variable is actually a resource. Because it is.
You need to get the result from the query before using it. The query returns a resultset just like any other query, but with only 1 row and 1 field.
$countQuery = mysql_query('SELECT COUNT(*) FROM Articles');
$count = mysql_result($countQuery, 0);