Original sentence: Letting the number of time intervals per year grow without bound leads to the definition
Edited sentence: A definition using a series or differential equation is more common in mathematics.Letting the number of time intervals per year grow without bound leads to the definition as the limit.The deriviative (rate of change) of the exponential function is equal to its current value.which corresponds to saying that adding two rates of interest would multiply the total amount by the same factor as applying each in turn separately