Introduction to Highest Common Factor and Euclid's Division Algorithm

The video tutorial covers positive integers and their common factors, focusing on the highest common factor (HCF) or greatest common divisor (GCD). It explains two methods to find the HCF: multiplication and division. The division method is further explored with examples, including cases with non-zero remainders, leading to the introduction of Euclid's division lemma and algorithm. The tutorial emphasizes the practical application of these methods, especially for larger numbers.

What is the highest common factor of 12, 30, 42, and 18?

• 3

• 2

• 12

• 6

Which method is NOT used to find the highest common factor?

• Both A and B

• Subtraction

• Division

• Multiplication

In the multiplication method, what is the HCF of 30 and 15?

• 5

• 10

• 15

• 20

When using the division method, what should you do if the remainder is not zero?

• Multiply the numbers again

• Stop the process

• Use the quotient as the new divisor

• Use the remainder as the new divisor

What is the HCF of 32 and 15 using the division method?

• 3

• 1

• 2

• 5

Why is the division method preferred for larger numbers?

• It is more accurate

• It is faster

• It avoids listing all factors

• It uses simpler calculations

What is Euclid's division lemma used for?

• Finding the sum of two numbers

• Finding the product of two numbers

• Finding the HCF of two numbers

• Finding the difference between two numbers