This is taught in american middle schools and high schools. Multiple times; it's the defacto example of how exponents work. It is not explicitly called out in

This is taught in american middle schools and high schools. Multiple times; it's the defacto example of how exponents work. It is not explicitly called out in the Common Core standard, but several of the examples in the common core are interest rate problems. Here's an example from the California Standard, search for 'interest'. http://www.cde.ca.gov/be/st/ss/documents/ccssmathstandardaug2013.pdf http://www.cde.ca.gov/be/st/ss/documents/ccssmathstandardaug...