This open access book examines the history and role of money. Money is often defined in terms
of three interrelated functions: as a medium of exchange store of value and unit of account.
Researchers frequently discuss the first two functions but tend to ignore unit of account.
This book focuses on how a unit of account or denomination can be defined and can be derived
from the monetary system. In the case of paper money and coins we know how to determine the
denomination of money based on the problem of the least number of weights defined by Bâchet and
proved by Hardy and Wright (1960). However in the case of digital or cryptocurrency
denomination may not matter because digital or cryptocurrency uses a wallet that is essentially
denomination free: a wallet can contain any amount of currency without upper and lower limits.
When people talk about the stablecoin i.e. the stable price of digital and cryptocurrency with
the major legal tender they take a unit of account or denomination of digital or
cryptocurrency as given. This arrangement destroys the nature of denomination free or
decentralized autonomy as it were. Exploring how we can consolidate with these two views of
denomination this book will appeal to anyone interested in creating new digital or
cryptocurrencies. It also serves as a textbook on central bank digital currency.
