Joanna – you should really join the living math yahoo group. I think you would enjoy it (I know I have!) and you have a lot to offer the discussion as well. It is a wonderful group and it is run by the owner of the living math site.
http://groups.yahoo.com/group/livingmathforum/
I believe the members of the group addressed through discussion some of the reservations expressed above about the Number Devil, maybe you could find the discussion by searching the archives? It was a while back, maybe in the last year though.
We loved “Number Stories of Long Ago”. We did it last year as a read aloud (ages 6 and 10 then) and mostly just skipped over the problems at the end of the chapter, or did a few orally. Along with the movie “The Story of 1“, it really made a big impression.
I bought Penrose the Mathmatical Cat last year and LOST IT!!!! I have been looking for it for months :(I know that as soon as I break down and buy it again it will turn up somehow.
We have also read several of the Sir Cumference books, as well as a couple of Murderous Maths, and Grandfather Tang’s story (tangrams) comes to mind…Also The Greedy Triangle.
Thanks for bringing this up as it seems to me that a CM education should include living books about math, but they are not as commonly discussed on CM sites as are books in the other subject areas.