This is not about counting change for point-of-sale transactions; how does retail use Mathematics beyond intermediate algebra? Or does retail business use much or any Mathematics beyond intermediate algebra? Anything like with linear algebra, or linear optimization, or any sort of topics to figure how to utilize space or to count inventory or to predict flow of inventory or people...? Would any kind of sophisticated mathematical modeling be done in retail companies to predict or control operations in their stores?
You can use an area of mathematics called operations research. Here is a definition from Informs: "Operations Research (O.R.), or operational research in the U.K, is a discipline that deals with the application of advanced analytical methods to help make better decisions. The terms management science and analytics are sometimes used as synonyms for operations research." For example, you can use queuing theory to find the ideal level of service for a retail business such as a supermarket. Here is a paper about modelling such a situation: http://www.statistics.du.se/essays/D07E.Nafees.pdf
you can also use it in R&D of your product and in survey-type stuff to measure the effectiveness of your product