Trenton Lee Stewart, The Mysterious Benedict Society and the Prisoner's Dilemma

"You've read half the books in this house? This whole house?""Well, approximately half."Sticky said. "To be more accurate, I suppose I've read more like"- his eyes went up as he calculated - "three sevenths? Yes, three sevenths.""Only three sevenths?"said Kate, pretending to look disappointed. "And here I was prepared to be impressed."