Are you smarter than a 3rd grader? My 3rd grade sister apparently isn't.
Question from "Brain Quest: Math Basics (3rd Grade)" (bolding added by me) was this: "Mr. and Mrs. Lee are the parents of 3 sons. Each son has 1 sister. How many children in all?"
She thought it was six, which makes total sense. One girl to each boy: three boys, three girls, six children total. Apparently, though, it's four. Why? Because that book is irritating.
The answer: "Four. The brothers all have the same sister."
THE FUCK? I believe a nice XKCD comic is necessary here.