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; ordering the associated numerical values contained in said set; defining a plurality of results groups, each results group comprising an interval of ordered numerical values, each interval having a range not exceeding the tolerance; ranking the results groups; and returning at least the interval of the highest ranked results group as a response to said query.