👉 Subtotals are a type of summary data that is calculated by adding up all the values in a list or set. Each subtotal represents the total amount of a specific item or product, and it can be added together to give an overall total for the group. For example, consider a list of items with their respective prices: ``` Item | Price --------|------- A | 10.5 B | 20.3 C | 30.4
