Written by an "industrial" statistician (running a company analyzing airline passenger traffic), this book analyzes results of job applications targeted to evaluate real life math skills. The results are surprising, in particular for these self selected sample of population applying for jobs requiring these skills. So what is the result of adding 2 apples to 5 oranges?
Some (or possibly many) of us got good grades in math, and indeed claim to be proficient in math. But as this book shows, without the correct semantics applied, math skills just not quite working right. Many of us cannot abstract relationships, cannot estimate (including estimating the population of the USA, which is a really basic number for somebody dealing with airline passenger counts ...), do not recognize 0 is a number, cannot round numbers, do not understand percentages, cannot convert minutes to hours, and the list goes on.
Part philosophical treatise, part personal reminiscences, part child/adult development discussion, lessons in history, part self help, overall a strange package of fun.
Oh, and to above question, 7 fruits would be a good answer :)