Interpretivism rejects the the Positivist claim that social reality can be studied objectively the way we study physical occurrences. In addition, positivists believe that we can use mathematics to construct a formal model or explanation of a social phenomena. If Interpretivism rejects the objective analysis of social reality, does it mean that it also rejects the use mathematics in doing research?
No. Statistics, a form of mathematics, is a key tool for sociologists. Standard deviations, mean, averages, remember the "Bell Curve" controversy?