Final answer:
The characteristic of money that allows for a consistent numerical metric in various forms is its role as a measure of value, specifically as a standard unit of account.
Step-by-step explanation:
The characteristic of money that explains that currency has a consistent numerical metric, whether the dollar is in the form of an old dollar, a new dollar, or as one hundred one-cent pennies is it being a measure of value. As a measure of value, money acts as a common denominator, an accounting method that simplifies transactions by giving a specific value to goods and services regardless of the form of money. A $20 bill holds the same value as 2,000 pennies because money is a standardized unit of account that allows for the equivalent value consideration, which is vital for pricing, record-keeping, and economic decision-making.