Math for Smarty Pants by Marilyn Burns
Oh how my Jane adores this book, and others in the Brown Paper School Books series! Other favorites are:
I find her curled up in bed with these books at night. On long car trips, it’s a sure bet that at least one of them makes the cut for her travel bag. Once we loaned Math for Smarty Pants to a friend, and I thought Jane was going to explode with impatience during the week or so this precious book was out of her possession. She is constantly regaling me with Fascinating Tidbits About Math and Other Stuff she has picked up from one of the Brown Paper School books. The cartoony, chatty style is what first roped her in, but it’s the wealth of puzzles, tricks, and “really cool facts” that keeps drawing her back.