My students loved this project. After a unit on ratios and proportions, I did a mini-lesson on the Fibonacci Sequence and the Golden Ratio. This projects asks the kids to discover whether or not any of their body measurement ratios match the Golden Ratio. I saw lessons similar to this on the internet, but this includes diagrams, tables, and notes that help scaffold the lesson for the students.
The students loved getting out of their seats and doing all the measurements, and were surprised to see all of the proportions that exist in the human body.
There are many extensions you can do after this lesson: Fibonacci Sequence, Leonardo Da Vinci, Mondrian, Statue of Liberty, etc.