Answer:
In the first instance money serves as Unit of account
In the second instance money serves as Medium of Exchange
Step-by-step explanation:
Money as Unit of Account: Money is a standard unit of account which means that money is common standard for measuring relative worth of goods and services.
In the first instance the super Slurpee is measured against the money and it is decided that amount of $1.39 is equal to the worth of super Slurpee.
Money as Medium of Exchange: Money acts as medium of exchange for the transactions to occur.
In the second instance, after the worth of super Slurpee has been decided in terms of money, $1.39 are exchanged for the super Slurpee.