@article {MATHEDUC.02336008,
author = {Smith, Will},
title = {The 72 rule and other approximate rules of compound interest.},
year = {2000},
journal = {Parabola [electronic only]},
volume = {36},
number = {1},
issn = {1446-9723},
pages = {7-15},
publisher = {AMT Publishing, Australian Mathematics Trust, University of Canberra, Canberra; School of Mathematics \& Statistics, University of New South Wales, Sydney},
abstract = {There is a simple approximate rule of thumb used by investors and accountants to estimate the time taken in years, $n$, for an investment to double with an interest rate of $R\%$, or indeed for a debt to double if left unpaid. One simply divides 72 by $R$ to estimate the time in years. The rule is known as ``Rule 72'' or ``the 72 Rule'' and is often attributed to the investment advisor Henri Aram who popularized it. This rule and a more accurate approximation are derived and discussed.},
msc2010 = {F80xx},
identifier = {2000f.04345},
}