Prime Numbers Worksheet (With Answers) (Page 2 of 2) in pdf

Prime Numbers Worksheet (With Answers) Page 2

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Name

Date

Prime Numbers

A number whose only factors are 1 and itself is called

a prime number. The number 2 is a prime number because

the only factors of 2 are 1 and 2.

The number 4 is not a prime number. The number 4 has three

factors, 1, 2, and 4.

Think about the definition of prime numbers and different ways to make

products to solve the following problems.

List the numbers from 3 through 10. Which numbers are prime? Which are not

prime? How do you know?

3, 5, and 7 are prime; 4, 6, 8, 9, and 10 are not prime. 3, 5,

and 7 only have the factors 1 and 3, 5, or 7.

Are any of the following numbers prime: 6, 8, 10, 12, 14, 16, 18? Explain.

No, because the number 2 is also a factor of each of

these numbers.

Look at the numbers in problem 2. What do these numbers have in common?

They are all even numbers.

The number 2 is even and it is a prime number. Are there other even numbers

that are prime numbers? Explain.

No, all other even numbers have the number 2 as a factor.

Explore It A number that is not a prime number is called a composite

number. On a separate sheet of paper, list the numbers from 2 through 18. Tell

if each number is prime or composite. Write two pairs of factors for each

composite number on the list.

Check students’ work.

Prime numbers: 2, 3, 5, 7, 11, 13, 17

Composite numbers: 4, 6, 8, 9, 10, 12, 14, 15, 16

Prime Numbers Worksheet (With Answers) Page 2