operation
noun:the act or manner of functioning, especially of a machine, system, or device
The operation of the machine is smooth and quiet.
She is recovering well from her knee operation.
noun:an organized and coordinated activity involving a number of people, especially for a specific purpose
The rescue operation saved dozens of people from the flood.
noun:a mathematical process, such as addition, subtraction, multiplication, or division, applied to numbers or variables
Division is an arithmetic operation that splits a quantity into equal parts.
noun:the day‑to‑day activities and processes of a business or organization
The company's overseas operations have grown significantly this year.