How many {creator} are to/by {United Nations Educational, Scientific and Cultural Organization} ?
How many nations found United Nations Educational, Scientific and Cultural Organization ?
The United Nations Educational, Scientific and Cultural Organization was created by how many?
SELECT ( COUNT ( ?p ) AS ?k ) { ?p property:creator resource:UNESCO }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P170> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q7809 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P170 wd:Q7809 }
13