Finding the Least Common Multiple Using Prime Factorization

Miacademy & MiaPrep Learning Channel

This educational math video demonstrates how to find the Least Common Multiple (LCM) of two numbers using the prime factorization method. The lesson begins by reviewing a simple example with small numbers to establish the concept, then introduces a more complex problem with large numbers to illustrate the limitations of the traditional "listing multiples" method. Through step-by-step demonstrations, the narrator shows how to build factor trees and use the resulting prime factors to efficiently construct the LCM. The video focuses on two main examples: finding the LCM of 8 and 12, and finding the LCM of 210 and 260. The core theme is efficiency in mathematical problem-solving. By contrasting the tedious process of skip-counting large numbers with the elegant solution provided by prime factorization, students learn not just *how* to use the method, but *why* it is a valuable tool in their mathematical toolkit. This resource is highly valuable for upper elementary and middle school classrooms as it bridges the gap between basic arithmetic and number theory. Teachers can use this video to introduce the concept of prime factorization as a practical tool rather than an abstract exercise. The visual representation of factor trees and the logic of selecting the necessary prime factors to "build" the LCM provides a strong conceptual foundation for later algebraic concepts involving common denominators and polynomial factoring.