It's Grandma's birthday, and Ruby knows exactly what Grandma would love — a beautiful ballerina box. Max also knows what she'd love — a scary pair of ooey-gooey vampire teeth. Ruby has saved up a wallet full of bills, but as one mishap leads to another, money starts running through the bunnies' fingers. . . . Will they have enough left for the perfect present? Wells' adorable story is also a fun and lively introduction to early math.