Here’s an example I like of a negative number times another

negative number equaling a positive number:

I have been giving away five dollars each minute.

Currently, at time t = 0, I have zero dollars, but I am continuing

to give away five dollars each minute in the form of IOU’s.

Thus, the equation for the number of dollars I have at time t is

D = -5t, where D represents dollars.

Using that equation, calculate how many dollars I had four

minutes ago.

Without giving this too much thought it seems that the answer is $20. Am I missing something?.

S. Rich

zisher@gmail.com

The fact that it was the product of two negative numbers?