SQA National 5 Computing Science Practice Exam

The arithmetic logic unit (ALU) is a fundamental component of the CPU that is responsible for performing various types of arithmetic operations, such as addition, subtraction, multiplication, and division, as well as logical operations. When considering the examples provided, the calculation of the sum of two numbers directly correlates with the primary function of the ALU.

In this context, when the ALU receives two numerical inputs, it performs addition as an operation, which aligns with its capabilities. This process is essential for a myriad of computations that occur in programming, mathematical calculations, and data processing within a computer system.

The other scenarios do not involve the functions typical of an ALU. For instance, transmitting data to storage devices pertains more to data flow and storage management, scanning for network security threats involves security protocols and monitoring, and formatting a hard drive is related to data organization and file system management. These tasks require different components and operations that are distinct from the basic arithmetic functions performed by the ALU.