Prime Factorisation To Find HCF & LCM

This video tutorial explains how to find the highest common factor (HCF) and the lowest common multiple (LCM) using prime factors. It begins with an introduction to these concepts and suggests watching prerequisite videos if needed. The tutorial then demonstrates how to find the LCM by taking the largest power of each prime factor from the numbers involved. It follows with a method to find the HCF by identifying common prime factors. The video concludes with a summary of the techniques and encourages viewers to practice these skills for efficiency. Viewers are also invited to engage with the content by liking, subscribing, and commenting.

What should you do if you're unsure about finding prime factors before learning about HCF and LCM?

• Skip the video and move on to the next topic.

• Watch the two recommended videos for a recap.

• Ignore the concept of prime factors.

• Try to solve problems without understanding the basics.

How do you determine the lowest common multiple of two numbers?

• By multiplying the numbers directly.

• By adding the numbers together.

• By taking the smallest power of each prime factor.

• By taking the largest power of each prime factor from either list.

When finding the highest common factor, what should you consider?

• All prime factors from both lists.

• Only the largest prime factors from both lists.

• The sum of all prime factors.

• Only the common prime factors from both lists.

What is the benefit of using prime factorization to find HCF and LCM?

• It requires no mathematical calculations.

• It avoids writing out all factors or multiples.

• It is only useful for small numbers.

• It is slower but more accurate.

What should you do after finding the HCF and LCM using prime factors?

• Always write out all factors and multiples.

• Memorize the skill for faster calculations.

• Forget the method as it is not useful.

• Only use it for small numbers.