i bought one and then immediately bought another for my daughter.  Here's  a fun quiz question you have to get right or you are not qualified for the book.  In the index, the first entry for 'A' is abacus and the first entry for 'B' is Babbage, Charles.  What is the first entry for 'E'?<br><br>Yeah I know it's dumb, but you have to agree that even if you can't guess it, you do see the humor - if not, don't buy the book.