Financial structs such as balance requires predicted precition with calculation, commonly number of any type can be used to store money amount, such as integer, float or even string. Unify approach to avoid round missunderstanding. For example bank and finantial program can use different approach so difference in result of prognosis can reach sensitive level, in some cases about few percent. Firstly I tryed to implement my own Dec type based on three integer values, but I met what bank count me more money than my program prognose.