When I was on vacation a couple weeks ago, I was inspired by the Feynman lectures on physics to review basic calculus. This time I tried my best to understand

When I was on vacation a couple weeks ago, I was inspired by the Feynman lectures on physics to review basic calculus. This time I tried my best to understand derivatives at a low/basic level. When I was in college, many years ago, I was doing my best to just to tread water in physics and the early stages of the calculus classes. I did my level best to try to explain derivatives as if I knew nothing of calculus. Used my wife as a guinny pig. What I ended up with explained both derivatives and integrals at the same time in a very basic, but correct (I believe) sort of “add up the arrows” sort of way. I really struggled to do this, but I thought it was really cool when I finished. Well finished is perhaps too strong a term. Most of it is scrawled out in handwriting on my iPad. I’ve been meaning to go back and wrap it up and put it on the web. I think I’ll try tonight and post back here or somewhere.