When one hears the word "code", pictures of computers, zeros and ones, and ciphers are most likely the things that come to mind. The Webster definition of code is "a system of signals used to represent letters or numbers in transmitting messages." Coding is simply defined as converting ordinary language into code. If these definitions were taken literally, the entire branch of mathematics could be placed under coding. In mathematics, we take ordinary language and convert it into symbols such as t and s. Thus the statement "Sally's age is six years fewer than twice that of Tim's" was to be written mathematically, it would be presented something like s=2t-6. Here s and t are symbols used to represent Sally's and Tim's ages respectively, while "=" symbolizes "is" and "-" denotes "fewer than". Although this example is rather elementary, it nonetheless portrays how coding is used in mathematics as a means of convenient symbolizing.
Simon, J. (2006). The Art of Coding Theory (Undergraduate honors thesis, University of Redlands). Retrieved from https://inspire.redlands.edu/cas_honors/32