I have three criteria for an excellent children’s math book: 1) it has to be exciting and intelectually accessible for children, 2) it has to hold my interest 3) it has to have good math.
The Grapes of Math by Gregory Tang, illustrated by Harry Briggs meets all of these criteria. Ostensibly it is a counting book, with lots of practice with mental addition and multiplication. Normally I would have no interest in such a book, so I was skeptical when my wife handed this one to me, but in truth this book is more about deep pattern-recognition schema fundamental to mathematics, while being appropriate for even the youngest children. I will say no more and let you check it out for yourself.