Final answer:
The cost of office supplies to be used in future periods is classified as an asset on the balance sheet and would be listed on the assets side of a T-account.
Step-by-step explanation:
The cost of office supplies to be used in future periods is ordinarily shown on the balance sheet as a(n) asset. This is because office supplies represent items of value that the business owns and will use in the future to produce something or carry out business activities. In a T-account format of a balance sheet, these supplies would be listed on the assets side, which is typically on the left-hand side. The T-account is designed to show a two-column format with assets on one side and liabilities on the other, making it clear how a firm's resources are financed.