Book 14: The Book of Perfectly Perilous Math by Sean Connolly
Talk about fun! This book offers "24 death-defying challenges for young mathematicians" to figure out and solve. I really enjoyed these mathematical mysteries. I also like how the book is arranged with cute graphics and illustrations to support the challenges. There's a worksheet at the end each challenge (but don't write on it if you checked out the book from the library). Definitely entertaining, and it makes math accessible and fun!