Arithmetic and Logic Unit 
The Arithmetic and Logic Unit are not a single entity, but are actually composed of two separate units whose operation is highly dependent on the Select Input(S).
This input, is a one-bit input, that will decide whether to route the binary variables to the Arithmetic, or to the Logic Circuit.
Arithmetic Unit 
Handles basic operations such as Addition and Subtraction. The Multiplication and Division operations are dependent on the basic operations, and Bit-Shifting. The Multiply and Divide operations, can also be implemented using Hardwired / Microprogrammed Control.
Logic Unit 
The Logic unit, is a Hardware Unit, implemented for performing basic operations such as AND, OR, NAND, and NOT. A particular logical operation is selected using a 4:1 Demultiplexer.
The results of all the operations are routed into a data bus for memory addressing.