This is an intuitive approach to the chain rule that I developed over the last few years ... Enjoy! I share this with my Calculus students so they are not mystified. Gwen Perea originally suggested the Science Learner as a sheet for her class, and she and I enjoyed the result so much that I took it to the next level while re-reading the Finney Calculus text. The pictures are from the MIT video from Annenberg Science website. Feedback appreciated.