Prime and Composite Numbers

•  

Grade Level

• Middle School

•  

Subject

• Mathematics

•  

Length of Time

• 45 Minutes To 1 Hour

•  

Description

• This lesson is on prime and composite numbers.

•  

Goals

• Students will learn:
  
  * What a prime number is.
  
  * What a composite number is.
  
  

•  

Materials Needed

• * You will need the worksheet that I have provided in this lesson.
  
  * Pencils and Erasers
  

•  

Procedure

• First, you will copy the worksheet I have included in this lesson. Then, you will explain the difference between prime and composite numbers.
  
  A prime number only has factors of 1 and the number.
  
  Example: 7 = 1 and 7. 1 x 7 = 7
  
  The factors of 7 are 1 and 7.
  
  Therefore, 7 is a prime number.
  
  A composite number has more than two factors.
  
  Example: 9 is a composite number.
  
  9 x 1 = 9
  
  3 x 3 = 9
  
  The factors of 9 = 1, 3, 9.
  
  After you have gone over some examples of prime and composite numbers, then you can pass out the worksheet.
  
  
  
  
  Worksheet: Prime and Composite Numbers.
  
  Directions: Write Prime or Composite after each number.
  
  1. 16 =
  
  2. 23 =
  
  3. 35 =
  
  4. 41 =
  
  5. 47 =
  
  6. 100 =
  
  7. 50 =
  
  8. 45 =
  
  9. 22 =
  
  10. 21 =
  
  11. 2 =
  
  12. 5 =
  
  13. 8 =
  
  14. 54 =
  
  15. 48 =
  
  16. 33 =
  
  17. 19 =
  
  18. 61 =
  
  19. 72 =
  
  20. 75 =
  
  
  
  
  Answer Sheet to Prime and Composite Numbers
  
  1. 16 = Composite
  
  2. 23 = Prime
  
  3. 35 = Composite
  
  4. 41 = Prime
  
  5. 47 = Prime
  
  6. 100 = Composite
  
  7. 50 = Composite
  
  8. 45 = Composite
  
  9. 22 = Composite
  
  10. 21 = Composite
  
  11. 2 = Prime
  
  12. 5 = Prime
  
  13. 8 = Composite
  
  14. 54 = Composite
  
  15. 48 = Composite
  
  16. 33 = Composite
  
  17. 19 = Prime
  
  18. 61 = Prime
  
  19. 72 = Composite
  
  20. 75 = Composite
  
  
  
  

•  

Grading

• Each question is worth five points.
  
  100 to 90 = A
  
  89 to 80 = B
  
  79 to 70 = C
  
  69 to 60 = D
  
  Below 60 = F
  
  

Sponsored Links