The book How Butterflies Came to Be (ISBN: 0021190399), which is part of the McGraw Hill Reading Wonders curriculum for Grade 2 (Unit 4, Week 4), can be classified by the following details: [1]

• Type: Leveled Reader / Children's Educational Book. It is a spiral-bound or softcover instructional text designed specifically for "On-Level" second-grade reading development. [1, 2, 3]
• Genre: Fiction / Folktale. Specifically, it functions as an origin or pourquoi tale, which is a traditional story that explains how something in nature came to be. [1]
• Subject: Elementary Reading & Language Arts mixed with Nature/Science themes. It is utilized to build reading fluency, comprehension skills, and vocabulary while connecting literature to scientific concepts. [1, 2]
• Topic: The mythical origin of butterflies. The story centers on a narrative explaining how butterflies were created, paired alongside themes of how forces or elements in nature adapt and change. [1]