Final answer:
Brookside clinic utilizes family or unit numbering to maintain a single medical record for Mary Adams and her three children, which streamlines recordkeeping.
Step-by-step explanation:
The type of numbering being used in the scenario provided, where Brookside clinic retrieves one record that contains patient information on Mary and her three children, is known as family numbering or unit numbering. This system assigns a single medical record number to all individual family members receiving care at the same healthcare facility. This approach helps to streamline recordkeeping and ensures that all familial records are easily accessible, simplifying patient care and follow-up.