About: http://webisa.webdatacommons.org/149051861

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	If you are talking about if the input value is a number, then you could check whether the value is a number before you attempt to multiply.
http://www.w3.org/ns/prov#wasQuotedFrom	daniweb.com