Michael Catchpool, David Roberts
Fred lived next door to Finn. Fred had 5 frogs, and so did Finn. But when the frogs hop over to each other's pads for nighttime parties and don't all return the next morning, Fred and Finn set out to build enormous barriers between their houses to keep their frogs from going next door. What follows is a little mathematical journey of counting fun as frogs clamor and climb their ways to night time frolicking.
My four year old son absolutely loves this book, and doesn't even realize that he's learning lots of math in the process!