Identifying Prime and Composite Numbers from 1-100

What is a prime number?

• A number that is even

• A number with more than two factors

• A number with exactly two factors

• A number with exactly one factor

Which of the following numbers is neither prime nor composite?

• 1

• 2

• 3

• 4

Why is the number 6 classified as composite?

• It is an even number

• It has exactly two factors

• It is a prime number

• It has more than two factors

Which of the following numbers is prime?

• 8

• 7

• 6

• 4

How can you tell if a number is even?

• It ends in 1, 3, 5, 7, or 9

• It ends in 0, 2, 4, 6, or 8

• It is a prime number

• It is divisible by 3

Which of the following numbers is composite because it ends in 5?

• 21

• 33

• 15

• 27

How can you determine if a number is divisible by 3?

• It is an even number

• The sum of its digits is divisible by 3

• It is a prime number

• It ends in 3

Which of the following numbers is prime?

• 55

• 53

• 51

• 49

Which of the following numbers is composite because it is divisible by 3?

• 21

• 23

• 19

• 17

Which of the following numbers is prime?

• 77

• 79

• 81

• 83