How many {child} are to/by {Gaia} ?
How many children does Gaia have?
SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P40 wd:Q93172 }
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/P40> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q93172 .
} 

What number of offspring does Gaia have?