Understanding Prime and Composite Numbers

The video tutorial introduces the concepts of prime and composite numbers, explaining how to determine if a number is prime or composite using factors and divisibility rules. It provides examples with numbers like 12, 13, 18, and others, and demonstrates the Sieve of Eratosthenes method to identify prime numbers. The lesson concludes with a brief mention of the next topic on number patterns.

What is the main difference between prime and composite numbers?

• Composite numbers have only one factor.

• Prime numbers have exactly two factors.

• Composite numbers have exactly two factors.

• Prime numbers have more than two factors.

Why is the number 1 not considered a prime number?

• It is a composite number.

• It is greater than two.

• It has only one factor.

• It is an even number.

Which of the following numbers is composite?

• 5

• 2

• 3

• 4

Using divisibility rules, determine if 51 is prime or composite.

• Composite, because it is divisible by 7.

• Prime, because it is not divisible by 2.

• Prime, because it is not divisible by 5.

• Composite, because it is divisible by 3.

Which number is a prime number?

• 55

• 53

• 51

• 49

What is the purpose of the Sieve of Eratosthenes?

• To find odd numbers.

• To find composite numbers.

• To find prime numbers.

• To find even numbers.

Which of the following numbers is not a prime number?

• 29

• 31

• 33

• 37

How many prime numbers are there less than 100?

• 25

• 20

• 35

• 30

What is the smallest prime number?

• 2

• 3

• 0

• 1

Which of the following statements is true?

• 1 is a prime number.

• 2 is the only even prime number.

• All odd numbers are prime.

• All even numbers are composite.