After a review of Books 1 and 2, Book 3 presents the Expository Paragraph. Three kinds of Expo Paragraphs are covered in Book 3: the Paragraph That Names Things, the Example Paragraph, and the Paragraph That Tells Why. As in previous books, students start from the ground up. They brainstorm, make lists, and use the number formula to construct simple paragraphs. From there, they learn how to write supporting sentences with sound reasons, add variety with quantity terms and details, and craft introductions and conclusions. By the end of the book, students are writing multiparagraph essays. Editing and revisiting old writing is encouraged, and the highly structured format fosters success. Every fourth or fifth lesson is a review.