Economists have long sought to integrate the subject matter of money into the general theory of the market. Various monetary doctrines and theories have been formulated to achieve this aim. However, most of them were refuted on the basis of inherent flaws in the arguments and/or conclusions. One of the standing theories of money is the quantity theory.
The old quantity theory of money proved helpful in providing the insight that the exchange-ratio between money and the various vendible goods and services can be determined in the same manner in which the mutual exchange-ratios between the various commodities are determined: by demand and supply. It essentially integrated the special instance of money into the broader theory of demand and supply.
This is about MoE and goes into Mises ideas on money He disproves the mathematical equations usefulness. This is the beginning of seeing that mathematics in not always useful in studies of human actions.