If you want to count *all* nodes, I assume you mean all descendants from
block. Use: count(//node()). If you want all nodes, but not the
whitespace or text nodes, use count(//*). If you want all nodes, but not
whitespace nodes, including text nodes, you can use count(//text()[.] |
//*). etc

Actually, rather count(.//node()), count(.//*), etc... unless the OP
wants to count all nodes in the document ;)