This column includes activities inspired by children's literature. When learning about a topic, scientists refer to documents from past researchers. This month's trade books include nonfiction and historical fiction selections that help to demonstrate similarities and differences "then and now" while incorporating engineering design ideas. In the first activity students will compare and contrast older toys or more simplistic toys to ones they have today by creating a written document that describes the physical properties of the toy. Students will also describe a new toy that they would like to see developed for the future. In the second activity students will consider an invention or process that has changed over time and the reasons for the change.