The request was for a parent with a mathematically curious child (really, could be anyone then, am I right?) of 4 or 5 years.
- Moebius Noodles, Maria Droujkova's great book about big math ideas to explore. There were articles about calculus in kindergarten when it first came out.
- Great new book: Which One Doesn¹t Belong. OK, I'll say more. I love this book because it's clever and pretty, but also because it can teach you how to read mathematically rich literature.
- Math Curse, Lane and Scieska: just the best math book ever written. Nearly anything can be a problem, you know.
- Anno's Mysterious Multiplying Jar, or anything by Mitsumasa Anno. Just charming books, and lovely besides.
- Spaghetti and Meatballs For All, Marilyn Burns: my favorite of the explicitly mathematical genre. Tang and Murphy have their place but Burns is the queen of the genre. (Greedy Triangle, Smarty Pants, $1 Word...)
- Princess of the genre, Elinor Pinczes: One Hundred Hungry Ants, A Remainder of One, ...
- Infinity and Me by Kate Hosford
- Tessallation! by Emily Grosvenor
- Grandfather Tang’s Story, by Ann Tompert
- The Dot and the Line, by Norton Juster
- Paul Erdos, The Boy Who Loved Math by Deborah Helligman
- Fibonacci, Blockhead by Joseph D'Agnese
- Eratosthanes, The Librarian Who Measured the Earth by Katherine Lasky
- Einstein usually gets lumped in here. Not a mathematician, technically, but if you're being that technical, loosen up! Try Odd Boy Out or On a Beam of Light
What to do:
- Chris Hunter has a bunch of recommendations plus how to use them.
- Another post with a lot of suggestions at Algebra's Friend
- Suzanne Alejandre suggested the old (aka classic) NCTM guide, Welchman-Tischler's book, might provide ideas? (She found a digital copy; use the NEXT button)
- Marilyn Burns (herself) just suggested this starting point from PBS
Possibly for older, but like Madeline L'Engle, I think people underestimate kids:
- The Phantom Tollbooth, by Norman Juster
- The Man Who Counted, by Malba Tahan
- Flatland, by Edwin Abbott
- The Number Devil, by Hans Magnus Enzensberger
- The Adventures of Penrose the Mathematical Cat, by Theoni Pappas
- The Cat in Numberland, by Ivar Ekeland and John O'Brien
- A Wrinkle in Time, Madeline L'Engle (First I heard of a tesseract.) There's an audiobook where L'Engle reads it herself. Highly recommended.
And please add your own suggestions!
- Cindy Whitehead saw that I missed the Sir Cumference books, by Cindy Neuschwander, and suggested the Go Figure books, by Johnny Ball.