Here is a 2 page document (could be copied back to back or single sided), for students to fill out on/near the 100th day of school. The first page asks students to draw a current self portrait of themselves and the next page asks the student to draw a picture of what they think they will look like when they are 100 years old. I showed my students pictures of 100 year olds/elderly people. We also brainstormed ideas of what you would see when looking at a 100 year olds. It is a cute, small journal entry in the end!