I thought the Math Curse by Jon Scieszka was a great book to read to kids at the beginning of the school year. It was full of fun images and silly jokes for the kids to enjoy. At the same time, it shows how mathematics are an important part of a student's everyday life. It goes through multiple kinds of math concepts, from addition to fractions in lots of goofy situations. You could use it just as a silly story or you could have kids solve some of the problems in the book.