This handy Spectrum Math Grade 4 Answer Key Chapter 4 Lesson 4.1 Prime and Composite Numbers provides detailed answers for the workbook questions.
Spectrum Math Grade 4 Chapter 4 Lesson 4.1 Prime and Composite Numbers Answers Key
A number is called prime if its only factors are 1 and itself.
For example, 7 is a prime number.
The only factors of 7 are 1 and 7.
A number is called composite if it has more than two factors.
For example, 8 is a composite number.
1, 2, 4, and 8 are all factors of 8.
List the factors of each number. Then, label each number as prime or composite.
Question 1.
64
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 64
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 64 = 1, 2, 4, 8, 16, 32, 64
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
Rest all 2, 4, 8, 16, 32, 64 are composite numbers as they have more than one factor.
Question 2.
43
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 43
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 43 = 1, 43
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
43 is a prime number
Question 3.
53
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 53
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 53 = 1, 53
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
53 is a prime number
Question 4.
72
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 72
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 72 = 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
3 is prime number as it have one and itself as factors.
Rest all 2, 4, 8, 12, 18, 24, 36 and 72 are composite numbers as they have more than one factor.
Question 5.
19
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 19
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 19 = 1, 19
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
19 is a prime number
Question 6.
48
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 48
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 48 = 1, 2, 3, 4, 6, 8, 12, 16, 24, 48.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
3 is prime number as it have one and itself as factors.
Rest all 1, 2, 3, 4, 6, 8, 12, 16, 24, and 48 are composite numbers as they have more than one factor.
Question 7.
22
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 22
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 22 = 1, 2, 11, 22.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
11 is prime number as it have one and itself as factors.
Rest 11 and 22 are composite numbers as they have more than one factor.
Question 8.
36
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 36
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, 36.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 is prime number as it have one and itself as factors.
Rest all 2, 4, 6, 9, 12, 18 and 36 are composite numbers as they have more than one factor.
Question 9.
89
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 89
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 89 = 1, 89
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
89 is a prime number
Question 10.
31
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 31
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 31 = 1, 31
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
31 is a prime number
Question 11.
93
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 93
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 93 = 1, 3, 31, 93.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 is prime number as it have one and itself as factors.
Rest 31 and 93 are composite numbers as they have more than one factor.
Question 12.
75
Factors
___________
Prime or Composite?
___________
Answer:
Given number is 75
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 93 = 1, 3, 5, 15, 25, 75.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 and 5 are prime numbers as it have one and itself as factors.
Rest 15, 25 and 75 are composite numbers as they have more than one factor.
List the factors of each number. Then, label each number as prime or composite.
Question 1.
80
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 80
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 80 = 1, 2, 4, 5, 8, 10, 16, 20, 40, 80.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
5 is a prime number as it have one and itself as factors.
Rest 2, 4, 8,10,16,20,40 and 80 are composite numbers as they have more than one factor.
Question 2.
55
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 55
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 55 = 1, 5, 11, 55.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
5 and 11 are prime numbers as it have one and itself as factors.
Rest 55 is a composite numbers as they have more than one factor.
Question 3.
28
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 28
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 28 = 1, 2, 4, 7, 14, 28.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
7 is a prime number as it have one and itself as factors.
Rest 2, 4, 14 and 28 are composite numbers as they have more than one factor.
Question 4.
67
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 67
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 67 = 1, 67
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
67 is a prime number
Question 5.
88
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 88
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 88 = 1, 2, 4, 8, 11, 22, 44, 88.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
11 is a prime number as it have one and itself as factors.
Rest 2, 4, 8, 22 , 44 and 88 are composite numbers as they have more than one factor.
Question 6.
73
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 73
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 73 = 1, 73
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
73 is a prime number
Question 7.
54
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 54
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 54 = 1, 2, 3, 6, 9, 18, 27, 54.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 is a prime number as it have one and itself as factors.
Rest 2, 6, 9,18,27 and 54 are composite numbers as they have more than one factor.
Question 8.
95
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 95
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 95 = 1, 5, 19, 95.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
5 is a prime number as it have one and itself as factors.
Rest 19 and 95 are composite numbers as they have more than one factor.
Question 9.
18
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 18
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 18 = 1, 2, 3, 6, 9, 18.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 is a prime number as it have one and itself as factors.
Rest 2, 6, and 18 are composite numbers as they have more than one factor.
Question 10.
91
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 91
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 91 = 1, 7, 13, 91.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
7 and 13 are prime numbers.
91 is a composite numbers as they have more than one factor.
Question 11.
57
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 57
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 57 = 1, 3, 19, 57.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite.
3 is a prime number as it have one and itself as factors.
Rest 19 and 57 are composite numbers as they have more than one factor.
Question 12.
13
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 13
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 13 = 1, 13
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
13 is a prime number
Question 13.
61
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 61
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 61 = 1, 61
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
61 is a prime number
Question 14.
77
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 77
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 77 = 1, 7, 11, 77.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
7 and 11 are prime numbers
77 is a composite number as they have more than one factor.
Question 15.
33
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 33
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 33 = 1, 3, 11, 33.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
3 and 11 are prime numbers
33 is a composite number as they have more than one factor.
Question 16.
23
Factors
__________
Prime or Composite?
__________
Answer:
Given number is 23
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 23 = 1, 23
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
23 is a prime number