Which mathematical operation would you use to determine the total quantity of items?

To determine the total quantity of items, the most appropriate mathematical operation is addition. When you are looking to find out how many items you have altogether, you sum the quantities of individual groups or items. For example, if you have 3 apples and 2 oranges, you would add them together to find the total quantity of fruits: 3 + 2 = 5. This operation effectively combines items from different groups to give a comprehensive count of all items present.

While multiplication can multiply quantities to get a total (such as finding out how many items are in several groups of the same size), it is used in different contexts, such as scaling or repeated addition. Division is reserved for sharing or partitioning items into equal groups and does not directly provide a total count. Subtraction, on the other hand, reduces quantities and is used to determine how many items remain after removing a certain number. Therefore, addition is the operation specifically designed to find the total quantity of items present.