In this lesson, which is the final one on number systems for fourth-year secondary school students, the focus is on performing multiplication and division using registers. The instructor explains how to utilize the left shift operation in binary numbers and its significance in these calculations. Additionally, the lesson covers concepts such as binary addition, subtraction, and the relevant rules that students need to study, emphasizing practical examples to illustrate these operations. Overall, students are guided through complex concepts in a structured way to enhance their understanding of binary calculations.