1. A method of querying a collection of electronic documents, comprising: defining a query for retrieving a numerical answer, said query comprising one or more search terms and a tolerance for said numerical answer; defining a set of document portions from said collection, each document portion in said set being extracted from an electronic document and comprising at least one term relevant to at least one of the one or more search terms and a numerical value associated with the at least one term; arranging the associated numerical values contained in said set in an order; defining a plurality of results groups, each results group comprising an interval of the arranged numerical values, wherein each interval is determined based on a difference between two of the arranged numerical values in the set, and wherein each interval has a range not exceeding the tolerance; ranking the plurality of results groups; and returning at least one interval of a highest ranked results group as a response to said query.