A complete set is 12. The titles are: From Head to Toe (Body Math) The Search for the Mystery Planet (Space Math) Play Ball (Sports Math) Alice in Numberland (Fantasy Math) How Do Octopi Eat Pizza Pie (Pizza Math) The Case of the Missing Zebra Stripes (Zoo Math) Right in Your Own Backyard (Nature Math) The Mystery of the Sunken Treasure (Sea Math) Look Both Ways (City Math) The House That Math Built (House Math) Pterodactyl Tunnel (Amusement Park Math) See You Later, Escalator! (Mall Math) And, no...they don't have to be done in any certain order.
Here are 3 more (sorry these are posting so big!). Hopefully these give you some idea what the inside of the books look like. There are a variety of art styles, some photos, some pages have more reading than others. If you can get the set, or piece it together, for a decent price...I think they are worth it. ETA: And, this shows you only 8 pages out of 756 pages (63 pages in each book), so you can probably see there is a lot of variety (way more than I could show). Plus each inside cover, front and back, is a game board (so 12 games).
Wow, thanks, they look awesome! I pulled out the puzzlemania books, I think they are too hard for her yet, she glanced through one and put it down saying that looks hard. I will revisit them in a year or two... but I will see about getting a few I Love Math books and grow the collection.