This document presents Booth's radix-4 algorithm for performing binary multiplication using an ALU. It explains that Booth's algorithm reduces the number of partial products generated during multiplication by grouping consecutive zeros and ones. It then describes the radix-2 Booth's algorithm and provides an example. The drawbacks of radix-2 are discussed, such as its inefficiency with isolated ones. Next, the radix-4 coding technique is presented and an example is shown. Finally, VHDL simulation code is presented to simulate multiplication using radix-4 algorithm.