The Secret Life Of Math: Discover How (and Why) Numbers Have Survived From the Cave Dwellers to Us! by Ann McCallum
Someone alerted me to this book published fairly recently, after I taught co-op classes and wrote lesson plans on early mathematics history. It is different than the primary readers I suggested for elementary kids for math history and is an outstanding resource. The History of Counting and From Zero to Ten: The Story of Numbers both tell the story of counting and number in a story-like way. "The Secret Life of Math" is more of an informational book, but the text is written in a kid-friendly tone. It is more readable than Joy Hakim's Story of Science, for those of you who have used that resource.
There are lots of insets, suggestions for activities, and really nice photographs of things like tally bones, tokens, quipus, of which the only good sources I could find a few years back were some out of print books or the internet.
It is arranged in three main sections: Keeping Track: How Humans Invented Methods; Writing It Down: Toward A Universal Language; and Faster Figuring: Knowing More - Sooner! Each section has chapters ranging from Hatch Marks, "Digit" Counting, Knots and Numbers, Roman Numerals, going from pebbles to symbols, cunieform, hieroglyphics, Zero, and the abacus, among others.
It is FULL of activities, is over 100 pages long, and is really a good value for one book. The layout is very attractive, colorful but not overly busy (in my opinion, I don't care for really busy books, although my kids sometimes do :o)
This one isn't as much for younger children as something like From Zero to Ten, I'd say generally age 8 on up, although your mileage may vary, some kids can handle things younger, some older, but I find this attractive myself, and can see it as a valuable family resource for a wide age range.