I am exuberantly excited about the book. My son is enjoying it, too. It makes so much more since to me to go ahead and explain these things at this age because it gives greater purpose to studying science at this age.Pro: The author's writing makes things relevant to early elementary. Pictures that truly illustrate a concept, like atoms and molecules are ideal, easy to understand, easy to remember.Con: There are pictures associated with reading passages that frequently have humor that is beyond a child's understanding and aren't really relevant to the passage or that. Sometimes they seem to be there just to fill space, to keep a page from being too full of text. The pages do have an appropriate amount of text, so I would give the illustrations 3 stars.This seller: "some highlighting" is an understatement. But it brought the price of the book down to where I was willing to buy and try. It arrived earlier than expected, so I would buy again.