Derivatives

In the car today...

E: Daddy!  The derivative is negative!
M: Indeed, the car is going down hill...
E: Daddy! For the cars going the other way, the derivative is positive!
M: Yes, Edwin...
E: What if the car goes backwards?
M: Well, the the derivative will be positive. The derivative with respect to time will be positive.  The derivative with respect to position will stay negative.
E: (giggles)

...

E: (giggling) Daddy! What is the derivative of time? (more giggles)
M: With respect to what? Time?
E: Yes!
M: That would be 1.
E: What if it was derivative of time respect to a clock?
M: If the clock was working correctly it would be 1
E: What if the clock was running backwards? (giggles) Would it be negative? Then the clock would ring at the wrong time!

Last night at Ledo's: Zachary and Edwin were both saying "This is the best ice cream I've ever had!". Theodore, who had been echoing many of the older boys' comments all night, decided to adjust the ending, saying "This is the best ice cream I've ever.... pooped in..."

"This restaurant is not only vegetarian and Chinese, it is also delicious!" Zachary. Rockville Pike. Vegan Restaurant.

Theodore helps with the firewood

Our heater is broken, but we have a fireplace, so all is well.  (It's also not cold out yet.)  Theodore helped bring some wood in for our fire this evening...

Compound third class lever

Edwin has been reading The New Way Things Work at night.  Since this was a book I spent many hours with as a child, I can often tell when something he remembers came from that book.  (It's a good way to tell he's actually reading...)  Today, when he was clipping his fingernails, he informed me "fingernail clippers use a compound third class lever".  Indeed, and he knew the definitions of examples of the other classes as well -- straight from the book.