The instability of the model can be resolved either by varying the exchange rate depending upon the amount of money the participant wishes to exchange, or by expanding the scope of is include in the exchange rate computation. Varying the rate, however, would complicate the presentation to participants and misdirect their attention to the model per se. Expending the scope resolves the problem by taking account money's unusual character, as an intangible created and destroyed by central and commercial banks at virtually no cost an in virtually no time. This approach directs participant's attention appropriately to money's inherent character. It will be discussed next