e (Euler's number)

Euler's number, approximately 2.718, is a fundamental mathematical constant. It naturally appears in processes involving continuous growth or decay, such as populations, money interest, or radioactive decay. Imagine continuously compounding interest: as earnings are constantly added to the principal, the total grows at a rate related to e. It also arises in calculus when dealing with exponential functions, where e is the unique base making certain derivatives simple. Overall, e is essential for understanding many natural and financial phenomena where change occurs smoothly and steadily over time.